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Moân hoïc: PHP Baøi 1 Nhöõng vaán ñeà chính seõ ñöôïc ñeà caäp trong baøi hoïc: Giôùi thieäu PHP Caáu hình IIS, Apache Web Server Caøi ñaët PHP. o Caøi ñaët PHP. o Caáu hình öùng duïng PHP Giôùi thieäu PHP. o PHP Script. o Ghi chuù trong PHP o In noäi dung baèng PHP PHP vieát taét cuûa chöõ Personal Home Page ra ñôøi naêm 1994 do phaùt minh cuûa Rasmus Lerdorf, vaø noù tieáp tuïc ñöôïc phaùt trieån bôûi nhieàu caù nhaân vaø taäp theå khaùc, do ñoù PHP ñöôïc xem nhö moät saûn phaåm cuûa maõ nguoàn môû. PHP laø kòch baûn trình chuû (server script) chaïy treân phía server (server side) nhö caùch server script khaùc (asp, jsp, cold fusion). PHP laø kòch baûn cho pheùp chuùng ta xaây döïng öùng duïng web treân maïng internet hay intranet töông taùc vôùi moïi cô sôû döõ lieäu nhö mySQL, PostgreSQL, Oracle, SQL Server vaø Access. Löu yù raèng, töø phieân baûn 4.0 trôû veà sau môùi hoã trôï session, ngoaøi ra PHP cuõng nhö Perl laø kòch baûng xöû lyù chuoãi raát maïnh chính vì vaäy baïn coù theå söû duïng PHP trong nhöõng coù yeâu caàu veà xöû lyù chuoãi.

1. GIÔÙI THIEÄU PHP

2. CAØI ÑAËT PHP
Caøi ñaët PHP treân neàn Windows thì söû duïng php-4.0.6-Win32.zip, sau khi caøi ñaët öùng duïng naøy treân ñóa cöùng seõ xuaát hieän thö muïc PHP, trong thöï muïc naøy seõ coù taäp tin php4ts.dll vaø php.exe cuøng vôùi thö muïc sessiondata. Ngoaøi ra, trong thö muïc WINDOW hoaëc WINNT seõ xuaát hieän taäp tin php.ini, taäp tin naøy cho pheùp baïn caáu hình cho öùng duïng PHP. Chaúng haïn, khi söû duïng session, PHP caàn moät nôi ñeå löu tröõ chuùng, trong taäp tin naøy maëc ñònh laø session.save_path = C:\PHP\sessiondata, neáu baïn caøi ñaët PHP vôùi thö muïc PHP treân ñóa D thì baïn caàn thay ñoåi ñöôøng daãn trong khai baùo naøy. Töông töï nhö vaäy, khi coù loãi trong trangPHP thì loãi thöôøng xuaát hieän khi trieäu goïi chuùng, ñeå che daáu caùc loãi naøy thì baïn caàn khai baùo display_errors = Off thay vì chuùng ôû traïng thaùi display_errors = On. Ngoaøi ra, trang PHP cuõng coù theå trình baøy moät soá warning khi chuùng phaùt hieän cuù phaùp khoâng hôïp lyù, chính vì vaäy ñeå che daáu caùc warning naøy thì baïn cuõng caàn khai baùo traïng thaùi Off thay vì On nhö assert.warning = Off.

3. CAÁU HÌNH ÖÙNG DUÏNG PHP
Sau khi caøi ñaët heä ñieàu haønh Windows NT hay 2000 trôû veà sau, baèng caùch khai baùo môùi moät web site hay virtual site trong moät site ñang coù theo caùc böôùc nhö sau: 1. Taïo moät thö muïc coù teân myPHP ñeà löu tröõ caùc taäp tin PHP 2. Khôûi ñoäng IIS (töï ñoäng khôûi ñoäng neáu Windows NT/2000)

3.1. Caáu hình IIS

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3. 4. 5. 6.

Choïn Start | Programs | Administrative Tools | Internet Information Server Neáu taïo virtual site thì choïn Default Web Ste | R-Click | New | Virtual Site Trong tröôøng hôïp taïo môùi Site thì Default Web Ste | R-Click | New | Site Neáu choïn tröôøng hôïp 4 thì baïn cung taáp dieãn giaûi cuûa site nhö hình 1-1

Hình 1-1: Khai baùo dieãn giaûi 7. Choïn nuùt Next vaø khai baùo IP vaø port, trong tröôøng hôïp baïn khoâng söû duïng port 80 cho öùng site khaùc thì choïn giaù trò maëc ñònh. Tuy nhieân neáu coù nhieàu öùng duïng tröôùc ñoù ñaõ caáu hình trong IIS thì baïn coù theå thay ñoåi port khaùc, ví duï choïn port 85 nhö hình 1-2.

Hình 1-2: Khai baùo IP vaø Port Löu yù raèng, port 80 laø port chuaån ñieàu naøy coù nghóa laø khi trieäu goïi treân trình duyeät baïn khoâng caàn goõ port, ví duï http://localhost/. Ñoái vôùi tröôøng hôïp port khaùc thì baïn phaûi goõ töông töï nhö http://localhost:85/

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8. Choïn Next, baïn choïn thö muïc cuûa öùng duïng, ñoái vôùi tröôøng hôïp naøy chuùng ta choïn vaøo thö muïc myPHP, chaúng haïn trong tröôøng hôïp naøy chuùng ta choïn htö muïc myPHP nhö hình 1-3.

Hình 1-3: Choïn thö muïc myPHP 9. Keá ñeán choïn quyeàn truy caäp web site, trong tröôøng hôïp ñang thieát keá thì baïn choïn vaøo Browse. Ngoaøi ra, neáu baïn cho pheùp ngöôøi söû duïng internet coù theå thöïc thi taäp tin thöïc thi töø xa thì choïn vaøo tuyø choïn execute.

Hình 1-4: Quyeàn truy caäp 10.Choïn Next vaø Finish, trong cöûa soå IIS xuaát hieän öùng duïng coù teân myPHP (khai baùo trong phaàn dieãn giaûi) nhö hình 1-5.

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Hình 1-5: Taïo thaønh coâng öùng duïng PHP trong IIS 11.Sau khi taïo öùng duïng xong, baïn choïn teân öùng duïng myPHP | R-Click } Properties | cöûa soå xuaát hieän nhö hình 1-5.

Hình 1-5: Caáu hình PHP trong IIS 12.Baèng caùch choïn vaøo nuùt Configuration, cöûa soå seõ xuaát hieän nhö hình 1-6.

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Hình 1-6: Theâm PHP Engine 13.Choïn nuùt Add, vaø khai baùo nhö hình 1-7.

Hình 1-7: Khai baùo PHP Engine 14.Ñeå kieåm tra uùng duïng, baïn môû cöûa soå IE vaø goõ treân thanh ñòa chæ chuoãi nhö sau: http://localhost:85/ , keát quaû xuaát hieän nhö hình 1-8.

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Hình 1-8: ÖÙng duïng PHP ñaõ ñöôïc khôûi ñoäng

3.2. Caøi ñaët Apache Web Servr
Ñeå caøi ñaët Apache Web Server, baïn theo caùc böôùc sau 1. Chep tap tin apache_1.3.22-win32-x86.exe xuong dia cung 2. Chay tap tin nay va cai dat len dia C:\Program Files\, sau khi ket thuc thanh cong phan cai dat Apache, baïn baét ñaàu caáu hình öùng duïng PHP. 3. Cheùp ba doøng leänh töø taäp tin install.txt trong thö muïc C:\PHP
ScriptAlias /php/ "c:/php/" AddType application/x-httpd-php .php Action application/x-httpd-php "/php/php.exe"

4. Paste vaøo taäp tin httpd.conf trong thö muïc Group\Apache\Conf\

C:\Program Files\Apache

5. Chon Start | Programs | Apache HTTP Server | Control Apache Server | Start 6. Viet trang test.php voi noi dung 7. Chep tap tin test.php Group\Apache\htdocs\ vao thu muc C:\Program Files\Apache

8. Sau ñoù goõ treân trình duyeät http://localhost/test.php

4. GIÔÙI THIEÄU PHP 4.1. Yeâu caàu
PHP döïa treân cuù phaùp cuûa ngoân ngöõ laäp trình C, chính vì vaäy khi laøm vieäc vôùi PHP baïn phaûi laø ngöôøi coù kieán thöùc veà ngoân ngöõ C, C++, Visual C. Neáu baïn xaây döïng öùng duïng PHP coù keát noái cô sôû döõ lieäu thì kieán thöùc veà cô sôû döõ lieäu MySQL, SQL Server hay Oracle laø ñieàu caàn thieát.

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4.2. Giôùi thieäu
PHP laø kòch baûn trình chuû (Server Script) ñöôïc chaïy treân neàn PHP Engine, cuøng vôùi öùng duïng Web Server ñeå quaûn lyù chuùng. Web Server thöôøng söû duïng laø IIS, Apache Web Server, ...

4.3. Thoâng dòch trang PHP
Khi ngöôøi söû duïng goïi trang PHP, Web Server trieäu goïi PHP Engine ñeå thoâng dòch (töông töï nhö ASP 3.0 chæ thoâng dòch chöù khoâng phaûi bieân dòch) dòch trang PHP vaø traû veà keát quaû cho ngöôøi söû duïng nhö hình 1-9.
Parse Web Server Taäp tin PHP

Request

Parse Request

Response Response

PHP Engine

P

Hình 1-9: Quaù trình thoâng dòch trang PHP

4.4. Kòch baûn (script)
Noäi dung cuûa PHP coù theå khai baùo laãn loän vôùi HTML, chính vì vaäy baïn söû duïng caëp daáu giaù ñeå khai baùo maõ PHP. Chaúng haïn, chuùng ta khai baùo: 1-Giaù trò bieán Str: 2-Giaù trò bieán i: 3-Giaù trò cuõ theå:

Chaúng haïn baïn khai baùo trang hello.php vôùi noäi dung nhö ví duï 1-1 sau: Ví duï 1-1: Trang hello.php ::Welcome to PHP Greeting:

Keát quaû traû veà nhö hình 1-10 khi trieäu goïi trang naøy treân trình duyeät.

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Hình 1-10: Keát quaû trang hello.php Trong tröôøng hôïp coù nhieàu khai baùo, baïn söû duïng Scriptlet, ñeàu naøy coù nghóa laø söû duïng caëp daáu treân nhö vôùi caùc khai baùo PHP vôùi cuù phaùp cuûa C nhö sau: -Khai baùo treân laø Scriptlet Giaù trò cuûa paging: -Khai baùo naøy laø Script

Löu yù raèng, keát thuùc moãi caâu leänh phaûi duøng daáu ; Ví duï, baïn khai baùo ñoaïn PHP treân trong taäp tin script.php nhö ví duï 1-2 Ví duï 1-2: Trang script.php ::Welcome to PHP Giaù trò cuûa paging:

Keát quaû traû veà nhö hình 1-11 khi trieäu goïi trang naøy treân trình duyeät.

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Hình 1-11: Keát quaû trang hello.php

Löu yù raèng, neáu baïn muoán söû duïng script hay scriptlet nhö ASP thì baïn khai baùo trong taäp tin php.ini nhö sau: asp_tags = On ; Allow ASP-style tags. maëc ñònh laø Off

Khi ñoù trong trang PHP, thay vì baïn khai baùo

Thì baïn coù theå khai baùo nhö sau:

4.5. Ghi chuù trong PHP
Ghi chuù trong kòch baûn PHP töông töï ngoân ngöõ laäp trình C, ñeå ghi chuù moät doøng thì baïn söû duïng caëp daáu /. Chaúng haïn khai baùo sau laø ghi chuù:

Trong tröôøng hôïp coù nhieàu doøng caàn ghi chuù baïn söû duïng caëp daáu /* vaø */, ví duï khai baùo ghi chuù nhö sau: Giaùo vieân: Phaïm Höõu Khang

COMPUTER LEARNING CENTER /* Khai baùo bieán ñeå ñoïc döõ lieäu trong ñoù totalRows laø bieán traû veà toång soá maåu tin */ $result = mysql_query($stSQL, $link); $totalRows=mysql_num_rows($result);

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Ngoaøi ra, baïn cuõng coù theå söû duïng daáu # ñeå khai baùo ghi chuù cho töøng doøng, ví duï khai baùo sau laø ghi chuù:

4.6. In keát quaû treân trang PHP
Khaùc vôù caùc kòch baûn nhö ASP, JSP, Perl, ñoái vôùi PHP ñeå in ra giaù trò töø bieán, bieåu thöùc, haøm, giaù trò cuï theå thæ baïn coù theå söû duïng script nhö treân:
Giaù trò cuûa paging:

Tuy nhieân, ñeå söû duïng cuù phaùp cuûa PHP khi in ra giaù trò töø bieán, bieåu thöùc, haøm, giaù trò cuï theå thì söû duïng khai baùo echo nhö sau: $stSQLs=”select * from Customers”; echo $stSQLs;

Chaúng haïn, khai baùo echo nhö ví duï 1-3. Ví duï 1-2: Trang echo.php ::Welcome to PHP

Keát quaû traû veà nhö hình 1-12 khi trieäu goïi trang naøy treân trình duyeät.

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Hình 1-11: Keát quaû trang hello.php

5. KEÁT LUAÄN
Trong baøi naøy, chuùng ta taäp trung tìm hieåu caùch caøi ñaët PHP vaø Apache Web Server, sau ñoù caáu hình öùng duïng PHP trong IIS hay söû duïng caáu hình maëc ñònh cuûa chuùng. Ngoaøi ra, baïn laøm quen caùch khai baùo maõ PHP trong trang .php cuøng vôùi script hay scriptlet.

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Moân hoïc: PHP Baøi 2

Baøi hoïc naøy chuùng ta seõ laøm quen vaø tìm hieåu cuù phaùp vaø moät soá phöông thöùc cô baûn cuûa PHP:
Caâu leänh. Kieåu döõ lieäu vaø bieán Khai baùo vaø söû duïng haèng. Döõ lieäu maûng Chuyeån ñoåi kieåu döõ lieäu

1. KHAÙI NIEÄM VEÀ CUÙ PHAÙP PHP

Cuù phaùp PHP chính laø cuù phaùp trong ngoân ngöõ C, caùc baïn laøm quen vôùi ngoân ngöõ C thì coù lôïi theá trong laäp trình PHP. Ñeå laäp trình baèng ngoân ngöõ PHP caàn chuù yù nhöõng ñieåm sau: Cuoái caâu leänh coù daáu ; Bieán trong PHP coù tieàn toá laø $ Moãi phöông thöùc ñeàu baét ñaàu { vaø ñoùng baèng daáu } Khi khai baùo bieán thì khoâng coù kieãu döõ lieäu Neân coù giaù trò khôûi ñaàu cho bieán khai baùo Phaûi coù chi chuù (comment) cho moãi feature môùi Söû duïng daáu // hoaëc # ñeå giaûi thích cho moãi caâu ghi chuù Söû duïng /* vaø */ cho moãi ñoaïn ghi chuù Khai baùo bieán coù phaân bieät chöõ hoa hay thöôøng

2. KHAI BAÙO BIEÁN
Khi thöïc hieän khai baùo bieán trong C, baïn caàn phaûi bieát tuaân thuû quy ñònh nhö: kieãu döõ lieäu tröôùc teân bieán vaø coù giaù trò khôûi ñaàu, tuy nhieân khi laøm vieäc vôùi PHP thì khoâng caàn khai baùo kieåu döõ lieäu nhöng söû duïng tieàn toá $ tröôùc bieán. Xuaát phaùt töø nhöõng ñieàu ôû treân, khai baùo bieán trong PHP nhö sau: $variablename [=initial value];
$licount=0; $lsSQL=”Select * from tblusers where active=1”; $nameTypes = array("first", "last", "company"); $checkerror=false;

Chaúng haïn, khai baùo nhö ví duï 2-1 (variables.php) ::Welcome to PHP

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Variable

3. KIEÅU DÖÕ LIEÄU
Baûng caùc kieåu döõ lieäu thoâng thöôøng Boolean Integer Float String Object Array True hay false giaù trò lôùn nhaát xaáp xæ 2 tyû ~1.8e308 goàm 14 soá leõ Löu chuoãi kyù töï chieàu daøi voâ haïn Kieåu ñoái töôïng Maûng vôùi nhieàu kieåu döõ lieäu

3.1. Thay ñoåi kieåu döõ lieäu
Ñeå thay ñoåi kieåu döõ lieäu, baïn coù theå söû duïng caùch eùp kieåu nhö trong caùc ngoân ngöõ laäp trình C hay Java. Chaúng haïn, khai baùo eùp kieåu nhö ví duï 2-2 (box.php): ::Welcome to PHP Variable

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Löu yù raèng, PHP töï ñoäng nhaän bieát giaù trò chuoãi ñaèng sau soá seõ khoâng ñöôïc chuyeån sang kieåu döõ lieäu soá nhö tröôøng hôïp treân. Ngoaøi ra, baïn coù theå söû duïng haøm settype ñeå chuyeån ñoåi döõ lieäu naøy sag döõ lieäu khaùc, ví duï chuùng ta khai baùo nhö ví duï 2-3 (settype.php). ::Welcome to PHP Change DataType of Variable

3.2. Kieåm tra kieåu döõ lieäu cuûa bieán
Ñeå kieåm tra kieåu döõ lieäu cuûa bieán, baïn söû duïng caùc haøm nhö sau: is_int ñeå kieåm tra bieán coù kieåu integer, neáu bieán coù kieåu integer thì haøm seõ traû veà giaù trò laø true (1). Töông töï, baïn coù theå söû duïng caùc haøm kieåm tra töông öùng vôùi kieåu döõ lieäu laø is_array, is_bool, is_callable, is_double, is_float, is_int, is_integer, is_long, is_null, is_numeric, is_object, is_real, is_string. Chaúng haïn, baïn khai baùo caùc haøm naøy nhö ví duï 2-4 (check.php). ::Welcome to PHP Check DataType of Variable

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3.3. Thay ñoåi kieåu döõ lieäu bieán
Khi khai baùo bieán vaø khôûi taïo giaù trò cho bieán vôùi kieåu döõ lieäu, sau ñoù baïn muoán söû duïng giaù trò cuûa bieán ñoù thaønh teân bieán vaø coù giaù trò chính laø giaù trò cuûa bieán tröôùc ñoù thì söû duïng caëp daáu $$. Ví duï, bieán $var coù giaù trò laø "total", sau ñoù muoán söû duïng bieán laø total thì khai baùo nhö ví duï 2-5 (change.php). ::Welcome to PHP Change DataType of Variable

3.4. Kieåu Array
Kieãu maûng laø moät maûng soá lieäu do ngöôøi duøng ñònh nghóa, chuùng coù cuù phaùp nhö sau: $myarrs=array("first", "last", "company"); // maûng bao goàm caùc kieåu chuoãi hay coù theå khai baùo nhö sau $myarr[]=array(3); $myarr[0]="Number 0"; $myarr[1]="Number 1"; $myarr[2]="Number 2"; Thöù töï index trong maûng baét ñaàu töø vò trí 0. Chaúng haïn, baïn khai baùo maûng moät chieàu theo hai caùch treân nhö ví duï 2-6 (array.php). ::Welcome to PHP Array on demenssion

Neáu nhö baïn khai baùo maûng hai chieàu, thì cuù phaùp khai baùo nhö sau: $myarrs[][]=array(2,3);

Chaúng haïn khai baùo nhö ví duï 2-7 (arrays.php): ::Welcome to PHP Array two demenssions

3.5. Kieåu ñoái töôïng
Ñeå khai baùo ñoái töôïng, baïn söû duïng khaùi nieäm class nhö trong ngoân ngöõ laäp trình C hay java, ngoaøi ra phöông thöùc trong PHP ñöôïc bieát ñeán nhö moät haøm. Ñieàu naøy coù nghóa laø töø khoaù laø function. Neáu haøm coù teân truøng vôùi teân cuûa class thì haøm ñoù ñöôïc goïi laø constructor. Chaúng haïn, chuùng ta khai baùo class vaø khôûi taïo chuùng thì töï ñoäng constructor ñöôïc goïi moãi khi ñoái töôïng khôûi taïo, sau ñoù goïi haøm trong class ñoù nhö ví duï 2-8 (object.php). ::Welcome to PHP Object

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echo "I am a regular function named B in class A.\n"; echo "I am not a constructor in A.\n";

3.6. Taàm vöïc cuûa bieán
Taàm vöïc cuûa bieán phuï thuoäc vaøo nôi khai baùo bieán, neáu bieán khai baùo beân ngoaøi haøm thì seõ coù taàm vöïc trong trang PHP, trong tröôøng hôïp bieán khai baùo trong haøm thì chæ coù hieäu löïc trong haøm ñoù. Ví duï, chuùng ta coù bieán $a khai baùo beân ngoaøi haøm nhöng khi vaøo trong haøm thì bieán $ ñöôïc khai baùo laïi, bieán naøy coùtaàm vöïec beân trong haøm. Töông töï nhö vaäy, khi bieán $i khai baùo trong haøm thì chæ coù taàm vöïc beân trong haøm cho duø chuùng ñöôïc khai baùo laïi beân ngoaøi nhö ví duï 2-9 (scope.php). ::Welcome to PHP Scope of Variable

Ngoaøi ra, ñeå söû duïng bieán toaøn cuïc trong haøm, baïn söû duïng töø khoa global, khi ñoù bieán toaøn cuïc seõ coù hieäu löïc beân trong haøm. Ví duï khai baùo bieán $a beân ngoaøi haøm, sau ñoù beân trong haøm Test baïn söû duïng töø khoaù global cho bieán $a, khi ñoù bieán $a seõ ñöôïc söû duïng vaø giaù trò ñoù coù hieäu löïc sau khi ra khoûi haøm chöù khoâng goáng nhö tröôøng hôïp trong ví duï scope.php nhö ví duï 2-10 (global.php). ::Welcome to PHP

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4. HAÈNG TRONG PHP 4.1. Khai baùo vaø söû duïng haèng
Haèng laø giaù trò khoâng thay ñoåi keå töø sau khi khai baùo, baïn coù theå söû duïng phaùt bieåu Define ñeå khai baùo haèng nhö sau: define("MAXSIZE", 100);

Ñeå söû duïng haèng, baïn khai baùo nhö ví duï 2-11 (constant.php) ::Welcome to PHP Constant

4.2.

Kieåm tra haèng

Khi söû duïng haèng, maø haèng chöa toàn taïi thì baïn söû duïng haøm defined nhö ví duï 212 sau (defained.php):

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5. KEÁT LUAÄN
Trong baøi naøy, chuùng ta tìm hieåu caùch khai baùo haèng, bieán vaø söû duïng haèng bieán. Ngoaøi ra, baïn cuõng tìm hieåu caùch chuyeån ñoåi kieåu döõ lieäu, kieåm tra kieåu döõ lieäu, taàm vöïec cuûa bieán.

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Baøi 3 PHEÙP TOAÙN VAØ PHAÙT BIEÅU COÙ ÑIEÀU KIEÄN TRONG PHP Chöông naøy chuùng ta seõ laøm quen vaø tìm hieåu toaùn töû, phaùt bieåu coù ñieàu kieän vaø voøng laëp cuûa PHP. Nhöõng vaán ñeà chính seõ ñöôïc ñeà caäp trong baøi hoïc naøy Toaùn töû. Pheùp gaùn trong PHP Phaùt bieåu coù ñieàu khieån. Voøng laëp.

1. KHAÙI NIEÄM VEÀ CAÙC TOAÙN TÖÛ TRONG PHP

Khi baïn laäp trình treân PHP laø söû duïng cuù phaùp cuûa ngoân ngöõ C, C++. Töông töï nhö nhöõng ngoân ngöõ laäp trình khaùc, toaùn töû giuùp cho baïn thöïc hieän nhöõng pheùp toaùn nhö soá hoïc hay treân chuoãi. Baûng sau ñaây giuùp cho baïn hình dung ñöôïc nhöõng toaùn töû söû duïng trong PHP, PHP ñònh nghóa toaù töû toaùn hoïc, quan heä, soá hoïc, bit vaø noät soá pheùp toaùn gaùn. Loaïi toaùn töû Toaùn töû + * / % > < >= < >= 2.2. Toaùn töû Not: ~ And !

Toaùn töû ~ ñaûo nghòch taát caû caùc bit cuûa tham soá, coøn toaùn töû ! ñaûo nghòch giaù trò cuûa giaù trò tröôùc ñoù. Chaúng haïn trong tröôøng hôïp naøy chuùng ta söû duïng cho bieåu thöùc hay bieán coù giaù trò boolean. Ví duï 3.2: Pheùp toaùn ~ and ! ::Welcome to PHP ~, ! Operator 2.3. Toaùn töû nhaân vaø chia: * and /

Baïn coù theå tham khaûo ví duï sau Ví duï 3.3: Pheùp toaùn * vaø /, + vaø ::Welcome to PHP

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Multi And Divide Operator 2.4. Toaùn töû modulus: %

Khi chia moät soá cho moät soá, baïn caàn keát quaû laø soá dö cuûa pheùp chia ñoù thì duøng toaùn töû modulus Ví duï 3.4: Pheùp toaùn % ::Welcome to PHP Mod Operator 2.5. Toaùn töû quan heä: >=,>,=, 2.7. Toaùn töû ?:

Toaùn töû naøy thay theá cho phaùt bieåu coù ñieàu kieän if...else, khi baïn caàn laáy keát quaû theo ñieàu kieän naøo ñoù, neáu coù theå khoâng caàn phaùt bieåu if-else, thì haõy thay theá baèng toaùn töû ?:, cuù phaùp cuûa chuùng nhö sau: str1=str2.equals(”khang”)?”Welcome to PHP”:”Good bye PHP”; Ví duï 3.7: Pheùp toaùn ?:

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::Welcome to PHP Selection Operators 3. PHEÙP GAÙN

Khi gaùn moät giaù trò hay bieán vaøo moät bieán trong PHP, baïn phaûi duøng ñeán pheùp gaùn, nhöng trong PHP cuõng gioáng nhö trong C thì coù nhöõng pheùp gaùn ñöôïc ñôn giaûn hoaù hay noùi ñuùng hôn laø chuaån hoaù ñeå ruùt goïn laïi trong khi vieát.
3.1. Pheùp gaùn thoâng thöôøng nhaát nhö sau:

$j=i; $str1 =” Hello!”; $b=true;
3.2. Pheùp gaùn theâm moät giaù trò laø 1

$k=0; $k++;
3.3. Pheùp gaùn chuoãi

$strX="Hello"; $strX.=” world”; $strX.=”ABCc”.$x;
3.4. Pheùp gaùn theâm moät vôùi chính noù giaù trò

$k=0;$j=1; $k+=$j; töông töï nhö vaäy chuùng ta coù $k*=2, nghóa laø $k=$k*2
4. PHAÙT BIEÅU COÙ ÑIEÀU KIEÄN

Caùc phat bieåu coù ñieàu kieän nhö : IF (ñieàu kieän) { caâu leänh; } IF (ñieàu kieän) { caâu leänh; }ELSE { caâu leänh; }

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IF (ñieàu kieän) { caâu leänh; }ELSEIF { caâu leänh; } switch (ñieàu kieän) { case Value1 caâu leänh1; break; } While (ñieàu kieän) Do - While (ñieàu kieän) Break Continue
4.1. Phaùt bieåu IF (ñieàu kieän) { caâu leänh; }

Söû duïng phaùt bieåu if ñeå choïn loïc keát quaû khi ñieàu kieän ñuùng, ví duï nhö sau: Ví duï 3.8: Phaùt bieåu IF ::Welcome to PHP IF Statement 4.2. Phaùt bieåu IF (ñieàu kieän) { caâu leänh; }ELSE { caâu leänh; }

Söû duïng phaùt bieåu if ñeå choïn loïc keát quaû khi ñieàu kieän ñuùng, vaø xuaát ra keát quaû khi ñieàu kieän sai, ví duï nhö sau: Ví duï 3.9: Phaùt bieåu IF - ELSE

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::Welcome to PHP IF ELSE Statement 4.3. Phaùt bieåu ELSEIF

Phaùt bieåu elseif laø phaàn cuûa phaùt bieåu if else nhieàu nhaùnh, khi coù nhieàu ñieàu kieän choïn löïa thì baïn söû duïng elseif, cuù phaùp cuûa chuùng nhö sau: ::Welcome to PHP ELSEIF Statement 4.4. Phaùt bieåu Switch (ñieàu kieän)

Phaùt bieåu switch laø phaàn cuûa phaùt bieåu elseif nhieàu nhaùnh, khi coù nhieàu ñieàu kieän choïn löïa thì baïn söû duïng switch, cuù phaùp cuûa chuùng nhö sau:

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Switch(ñieàu kieän) { case Value1 caâu leänh1; break; case Value2 caâu leänh2; break; … default: caâu leänh default; } Break: duøng ñeå thoaùt ra khoûi switch khi thoaû moät case naøo ñoù trong switch, default: khi khoâng coù baát kyø giaù trò naøo thoaûn trong caùc case thì giaù trò cuoái cuøng laø defaule statement Ví duï 3.10: Phaùt bieåu Switch ::Welcome to PHP SWITCH Statement 4.5. Phaùt bieåu While(ñieàu kieän)

true.

Phaùt bieåu while thöïc thi nhöõng caâu leänh trong while khi ñieàu kieän coù giaù trò

Ví duï 3.11: Phaùt bieåu While ::Welcome to PHP While Statement 4.6. Phaùt bieåu For

sau:

Phaùt bieåu for duøng cho voøng laëp coù giôùi haïn cho tröôùc, cuù phaùp coù daïng nhö

Ví duï 3.12: Phaùt bieåu For

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::Welcome to PHP FOR Statement 4.7. Phaùt bieåu do while

Phaùt bieåu do while cho pheùp duyeät vaø kieåm tra ñieàu kieän sau phaùt bieåu thöù nhaát, ñieàu naøy coù nghóa laø ít nhaát moät phaùt bieåu ñöôïc thöïc hieän. Ví duï 3.13: Phaùt bieåu Do While ::Welcome to PHP Do While Statement

Phaùt bieåu exit cho pheùp thoùat ra khoûi phaùt bieåu ñieàu kieän khi thoaû ñieàu kieän naøo ñoù. Ví duï 3.14: Phaùt bieåu exit ::Welcome to PHP Exit Statement 5. TOÙM TAÉT

Trong baøi hoïc naøy chuùng toâi giôùi thieäu ñeán cho caùc baïn caùc pheùp gaùn, caùc toaùn töû, ñoàng thôøi giuùp cho caùc baïn hieåu theâm vaøo caùc phaùt bieåu coù ñieàu kieän nhö while, for, switch, ….

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Moân hoïc: PHP Baøi 4

Baøi hoïc naøy chuùng ta seõ laøm quen vôùi bieán form vaø hai phöông thöùc $HTTP_POST_VARS vaø $HTTP_GET_VARS cuûa PHP:
Bieán form. Phöông thöùc $HTTP_GET_VARS Phöông thöùc $HTTP_POST_VARS

1. BIEÁN FORM
Bieán form trong PHP ñöôïc bieát ñeán nhö moät loaïi bieán, thay vì khai baùo thì bieán ñoù chính laø teân cuûa theû nhaäp lieäu trong trang submit hay tham soá treân querystring.

1.1. Bieán form töø form ñöôïc submit vôùi phöông thöùc POST
Trong trang baïn submit ñeán, neáu khai baùo teân cuûa theû naèm trong theû form coù teân laø xyz thì bieán form ñöôïc ñònh nghóa laø $xyz. Chaúng haïn, baïn khai baùo baùo theû form trong trang submit.php nhö ví duï 4-1. Ví duï 4-1: Khai baùo theû form
... Name: Gender : Male Female   ...

Khi ngöôøi söû duïng nhaäp giaù trò vaøo phaàn Name vaø choïn giôùi tính Male hay Female nhö hình 4-1, neáu nhaán nuùt submit thì trang ex1-1.php seõ trieäu goïi, trong trang naøy baïn coù theå laáy giaù trò nhaäp töø trang ex1.php baèng caùch söû duïng bieán form nhö ví duï 4-1-1. Ví duï 4-2: Duøng bieán form ::Welcome to PHP Form variable Name :

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Trong ñoù, $fullname vaø $gender laø teân cuûa hai theû input trong trang ex1.php, trong tröôøng hôïp naøy chuùng ta söû duïng phöông thöùc POST cho form.

Hình 4-1: Nhaäp lieäu

Keát quaû traû veà nhö hình 4-1-1.

Hình 4-1-1: Keát quaû laáy töø trang submit baèng bieán form

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1.2. Bieán form töø form ñöôïc submit vôùi phöông thöùc GET
Neáu baïn söû duïng phöông thöùc GET trong theû form, baïn coù theå laáy giaù trò cuûa caùc tham soá treân chuoãi QueryString baèng bieán form. Ví duï khai baùo theû form coù hai tuyø choïn nhö ví duï 4-2 vôùi phöông thöùc GET trong theû form. Ví duï 4-2: Khai baùo theû form
... Province : Ha Noi Ho Chi Minh Hue Industry : Automobile Foods Enginering Garment   ...

Khi trieäu goïi trang ex2.php treân trình duyeät, ngöôøi söû duïng choïn giaù trò trong hai tuyø choïn Province vaø Industry nhö hình 4-2.

Hình 4-2: Phöông thöùc GET

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Neáu nhaán Submit thì hai giaù trò choïn seõ ñöôïc truyeàn leân treân QueryString vôùi hai tham soá laø teân cuûa theû select. Ví duï trong tröôøng hôïp naøy keát quaû traû veà nhö hình 42-1.

Hình 4-2-1: Bieán form vôùi phöông thöùc GET Trong ñoù, hai tham soá vaø giaù trò töông öùng laø ex21.php?province=HAN&industry=FOO, baèng caùch söû duïng bieán form baïn coù theå laáy ñöôïc giaù trò naøy nhö ví duï 4-2-1. Ví duï 4-2-1: Khai baùo theû form ::Welcome to PHP Form variable Province : Industry :

Ñoái vôùi tröôøng hôïp baïn khoâng söû duïng theû form nhö hai tröôøng hôïp treân, chuùng ta cuõng coù theå laáy giaù trò töø chuoãi QueryString baèng bieán form. Chaúng haïn, baïn khai baùo trang chop pheùp ngöôøi söû duïng choïn kyù töï ñeå lieät keâ danh saùch khaùch haøng theo kyù töï ñoù nhö hình 4-3.

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Hình 4-3: Choïn kyù töï Baèng caùch khai baùo caùc theû baïn ñònh nghóa 24 kyù töï nhö hình treân vôùi tham soá al coù giaù trò töông öùng: A | B | C | D | E | All

Khi ngöôøi söû duïng choïn moät kyù töï thì söû duïng bieán form laø teân cuûa tham soá (al), baïn coù theå laáy ñöôïc giaù trò cuûa kyù töï ñang choïn:
Select:

Tuy nhieân, laán ñaàu tieân trieäu goïi trang naøy maø khoâng coù tham soá treân QueryString, khai baùo bieán form seõ phun ra loãi nhö hình 4-3-1. Ñeå traùnh tröôøng hôïp naøy, baïn söû duïng haøm isset ñeå kieåm tra bieán toàn taïi hay khoâng, neáu toàn taïi thì baïn söû duïng bieán form naøy. Ví duï ñoái vôùi tröôøng hôïp naøy chuùng ta khai baùo nhö ví duï 4-3. Ví duï 4-3: Söû duïng bieán form ::Welcome to PHP Form variable List by Alphabet

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Hình 4-3-1: Loãi phaùt sinh Chuù yù raèng, khi söû duïng bieán form baïn khoâng neân khai baùo bieán cuøng teân vôùi caùc tham soá hay teân cuûa theû nhaäp lieäu trong trang trieäu goïi tröôùc ñoù. Neáu khoâng thì giaù trò traû veà laø giaù trò cuûa bieán thöôøng thay vì bieán form.

2. PHÖÔNG THÖÙC $HTTP_GET_VARS
Ngoaøi caùch söû duïng bieán form trong tröôøng hôïp laáy giaù trò töø tham soá cuûa QueryString, baïn coù theå söû duïng haøm $HTTP_GET_VARS. Ví duï, chuùng ta khai baùo trang PHP nhö ví duï 4-4. Ví duï 4-4: Söû duïng $HTTP_GET_VARS

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Löu yù raèng, neáu baïn khoâng söû duïng haøm isset ñeå kieåm tra province toàn taïi hay khoâng thì trang php seõ phun loãi trong tröôøng hôïp laàn ñaàu tieân goïi ñeán trang ex4.php maø khoâng submit. Tuy nhieân, neáu baïn submit trang naøy thì keát quaû traû veà nhö hình 4-4.

Hình 4-4: Duøng $HTTP_GET_VARS Töông töï nhö vaäy trong tröôøng hôïp baïn khoâng söû duïng theû form maø giaù trò laáy töû chuoãi QueryString baèng caùch söû duïng $HTTP_GET_VARS nhö ví duï 4-5. Ví duï 4-5: Söû duïng $HTTP_GET_VARS ::Welcome to PHP

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Form variable List by Alphabet A | B | C | D | E | All Select:

Keát quaû traû veà nhö hình 4-5.

Hình 4-5: Söû duïng $HTTP_GET_VARS

3. PHÖÔNG THÖÙC $HTTP_POST_VARS
Töông töï nhö $HTTP_GET_VARS nhöng $HTTP_POST_VARS cho pheùp baïn laáy giaù trò laáy töø caùc theû nhaäp lieäu cuûa theû form trong traang submit tröôùc ñoù. Ví duï, baïn khai baùo trang nhaäp lieäu nhö ví duï 4-6. Ví duï 4-5: Khai baùo form vôùi phöông thöùc POST ::Welcome to PHP

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COMPUTER LEARNING CENTER Form variable User Name : Password :  

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Khi ngöôøi söû duïng nhaäp username vaø password nhö hình 4-6 vaø nhaán nuùt Login.

Hình 4-6: Ñaêng nhaäp Baèng caùch söû duïng $HTTP_POST_VARS ñeå laáy giaù trò username vaø password nhö ví duï 4-7. Ví duï 4-5: Söû duïng $HTTP_POST_VARS ::Welcome to PHP Form variable

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Username : Password :

Keát quaû trình baøy nhö hình 4-7.

Hình 4-7: Duøng $HTTP_POST_VARS

4. KEÁT LUAÄN
Trong baøi naøy, chuùng ta tìm hieåu caùch söû duïng bieán form vaø hai phöông thöùc $HTTP_POST_VARS, $HTTP_GET_VARS. Ngoaøi ra, baïn cuõng tìm hieåu caùch kieåm tra bieán toàn taïi hay khoâng baèng haøm isset(). Chuù yù raèng, khi söû duïng bieán form baïn traùnh tröôøng hôïp khai baùo bieán cuïc boä hay toaøn cuïc trong tang PHP cuøng teân vôùi theû nhaäp lieäu cuûa form tröôùc ñoù submit ñeán hay tham soá treân querystring.

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Moân hoïc: PHP Baøi 5

Baøi hoïc naøy chuùng ta seõ laøm quen vôùi ñoái töôïng Session vaø moät soá ñoái töôïng khaùc:
Ñoái töôïng Session. Ñoái töôïng khaùc

1. ÑOÁI TÖÔÏNG SESSION
Trong PHP4.0 ñoái töôïng Session ñöôïc xem nhö moät ñoái töôïng cho pheùp baïn truyeàn giaù trò töø trang PHP naøy sang PHP khaùc. Ñeå söû duïng Session, baïn khai baùo thö muïc ñöôïc löu tröõ döõ lieäu do ñoái töôïng nay ghi ra. Session ñöôïc sinh ra vaø ñöôïc bieán maát khi ngöôøi söû duïng huyû chuùng, thôøi gian soáng cuûa chuùng ñaõ heát hoaëc ngöôøi söû duïng ñoùng trình duyeät. Chaúng haïn, trong tröôøng hôïp naøy chuùng ta söû duïng thö muïc C:\PHP\sessiondata ñöôïc khai baùo trong taäp tin php.ini. session.save_path = C:\PHP\sessiondata

Ngoaøi ra, khi muoán söû duïng Sessoin thì baïn phaûi khôûi taïo chuùng. Ñeå khôûi taïo Session baïn coù theå khôûi taïo trong trang PHP moãi khi truy caäp hay gaùn giaù trò cho Session. session_start(); Tuy nhieân, baïn coù theå caáu hình trong trang php.ini (1 laø start). session.auto_start = 0

1.1. Nhaän daïng Session
Moãi phieân laøm vieäc ñöôïc taïo ra töø Web Server thì seõ coù moät nhaän daïng duy nhaát coù giaù trò laø chuoãi do trình chuû Web taïo ra. Ñieàu naøy coù nghóa laø moãi khi ngöôøi söû duïng trieäu goïi trang Web cuûa Web Site laàn ñaàu tieân thì phieân laøm vieäc seõ ñöôïc taïo ra, khi ñoù moät nhaän daïng ñöôïc caáp cho phieân laøm vieäc ñoù. Ñeå laán giaù trò nhaän daïng cuûa Session do trình chuû Web caáp phaùt baïn söû duïng cuù phaùp:
$x= session_id();

Chaúng haïn, baïn khai baùo baùo ñeå laáy giaù trò session_id trong trang sessionid.php nhö ví duï 5-1. Ví duï 5-1: Nhaän daïng session

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Moãi ngöôøi söû duïng truy caäp ñeán Web Site seõ coù moät nhaän daïng khaùc nhö nhö hình 51.

Hình 5-1: Nhaän daïng duy nhaát

1.2. Khai baùo Session
Khi muoán khai baùo bieán session, baïn phaûi söû duïng haøm session_register coù cuù phaùp nhö sau: session_register("sessioname"); Khi muoán khôûi taïo session, baïn coù theå gaùn giaù trò cho session naøy nhö gaùn giaù trò cho bieán trong PHP, sau ñoù söû duïng haøm treân ñeå ñaéng kyù.
$sessioname=value; session_register("sessioname");

Trong tröôøng hôïp coù nhieàu session, baïn coù theå söû duïng haøm session_register ñeå ñaêng kyù cuøng moät luùc nhieàu session nhö sau:
$sessioname1=value1; $sessioname2=value2;

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$sessioname3=value3; session_register("sessioname1","sessioname2","sessioname3");

Chaúng haïn, trong tröôøng hôïp naøy chuùng ta khai baùo trang sessionregister.php vaø ñaêng kyù 3 sessoin coù teân userid, email vaø fullname nhö ví duï 5-2 sau: Ví duï 5-2: Ñaêng kyù session ::Welcome to PHP Registered Session

Keát quaû traû veà nhö hình 5-2.

Hình 5-2: Ñaêng kyù Session

1.3. Laáy giaù trò töø session
Sau khi khai baùo khôûi aïo moät soá session vôùi giaù trò töông öùng cuûa session ñoù, baïn coù theå truy caäp caùc bieán session naøy ñeå laáy giaù trò torng trang PHP khaùc. Chaúng haïn, chuùng ta khai baùo trang getsession.php ñeå laáy caùc session cuûa PHP vöøa khai baùo trong ví duï treân nhö ví duï 5-3. Ví duï 5-3: Laáy giaù trò töø session Giaùo vieân: Phaïm Höõu Khang

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::Welcome to PHP Get Session

Khi trieäu goïi trang getsession.php treân trình duyeät baïn trình baøy giaù trò cuûa session userid, email vaø fullname nhö hình 5-3.

Hình 5-3: Laáy giaù trò cuûa session Tuy nhieân, trong tröôøng hôïp baïn truy caäp moät bieán session chöa khôûi taïo tröôùc ñoù thì l64i seõ phaùt sinh. Ví duï trong tröôøng hôïp naøy chuùng ta truy caäp bieán session coù teân $address nhö ví duï 5-4. Ví duï 5-4: Truy caäp session chöa toàn taïi ::Welcome to PHP

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Khi trieäu goïi trang unregistersession.php treân trình duyeät thì loãi phaùt sinh nhö hình 5-4.

Hình 5-4: Loãi phaùt sinh Ñeå kieåm tra session ñoù coù toàn taïi hay chöa baïn söû duïng haøm session_is_register trong trang checksession.php. Ñoái vôùi tröôøng hôïp naøy chuùng ta caàn kieåm tra 4 session tröôùc khi truy caäp ñeán chuùng nhö ví duï 5-5. Ví duï 5-5: Kieåm tra session ::Welcome to PHP Get Session

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Khi trieäu goïi trang checksession.php thì keát quaû seõ trình baøy nhö hình 5-5.

Hình 5-5: Khoâng coù loãi phaùt sinh Chuù yù raèng, khi söû duïng ñeán session, baïn phai khôûi ñoäng chuùng baèng session_start() neáu khoâng thì phaûi khai baùo trong php.ini.

1.4. Huyû session
Khi khoâng coù nhu caàu söû duïng session nöõa thì baïn söû duïng haøm session_unregister ñeå loaïi session ñoù. Chaúng haïn, trong tröôøng hôïp naøy chuùng ta muoán loaïi boû session coù teân laø fullname baïn khai baùo trong trang sessionunregister.php nhö ví duï 5-6. Ví duï 5-6: Loaïi boû moät Session ::Welcome to PHP

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Khi trieäu goïi trang sessionunregister.php treân trình duyeät thìkeát quaû traû veà nhö hình 56.

Hình 5-6: Loaïi boû session Trong tröôøng hôïp loaïi boû taát caùc session ñang toàn taïi thì söû duïng haøm session_unset(). Ví duï duøng haøm naøy ñeå laïoi boû session vaø duøng haøm sessin_destroy ñeå huyû taát caû session ñoù khai baùo trong trang unset.php nhö ví duï 5-7. Ví duï 5-7: Xoaù taát caû session ::Welcome to PHP UnSet Session

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Keát quaû traû veà nhö hình 5-7.

Hình 5-7: Huyû session

2. COOKIE
Cookie ñöôïc xem nhö session, tuy nhieân chuùng löu tröõ thoâng tin treân trình khaùch. Ñeå söû duïng Cookie, baïn söû duïng haøm setcookie ñeå gaùn giaù trò nhö ví duï 5-8. Ví duï 5-8: Gaùn giaù trò cho cookie ::Welcome to PHP Cookie

Khi ngöôøi söû duïng trieäu goïi trang setcookie.php keát quaû traû veà nhö hình 5-8.

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Hình 5-8: Ñaéng kyù cookie Ngaøi ra, baïn coù theå gaùn giaù trò cookie baèng session. Chaúng haïn, chuùng ta söû duïng haøm session_set_cookie_params ñeå gaùn cookie nhö ví duï 5-9. Ví duï 5-9: Gaùn cookie baèng session ::Welcome to PHP Session-Cookie

Baèng caùch söû duïng $HTTP_COOKIE_VARS ñeå laáy giaù trò cuûa cookie tröôùc ñoù trong trang httpcookievar.php nhö ví duï 5-10. Ví duï 5-10: Söû duïng $HTTP_COOKIE_VARS ::Welcome to PHP Get Cookie

Keát quaû trình baøy nhö hình 5-10.

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Hình 5-10: Duøng $HTTP_COOKIE_VARS Baèng caùch söû duïng haøm session_get_cookie_params ñeå laáy giaù trò cuûa cookie tröôùc ñoù trong trang sessiongetcookie.php nhö ví duï 5-11. Ví duï 5-11: Söû duïng session_get_cookie_params ::Welcome to PHP Get Cookie

3. KEÁT LUAÄN
Trong baøi naøy, chuùng ta tìm hieåu caùch söû duïng bieán session vaø cookie.

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Moân hoïc: PHP Baøi 6

Baøi hoïc naøy chuùng ta seõ laøm quen caùch khai baùo haøm, cheøn taäp tin vaø taäp tin duøng chung:
Caùch khai baùo haøm. Xaây döïng taäp tin ñònh daïng noäi dung Taäp tin duøng chung

1. KHAI BAÙO HAØM TRONG PHP
Haøm do ngöôøi söû duïng ñònh nghóa cho pheùp baïn xöû lyù nhöõng taùc vuï thöôøng laëp ñi laëp laïi trong öùng duïng. Ñeå khai bao haøm, baïn söû duïng töø khoaù function vôùi cuù phaùp töông töï nhö sau: function functioname($parameter) { return value; }

Trong tröôøng hôïp haøm khoâng coù giaù trò traû veà thì haøm ñöôïc xem nhö thuû tuïc. Ngoaøi ra, baïn coù theå khai baùo tham soá tuyø choïn baèng caùch gaùn giaù trò maëc ñònh cho tham soá. Ví duï chuùng ta khai baùo: function functioname($parameter1, $parameter2=10 ) { return value; }

Ñoái vôùi tröôøng hôïp naøy thì tham soá $parameter1 laø tham soá baét buoäc vaø tham soá $parameter2 laø tham soá tuyø choïn, khi goïi haøm neáu khoâng cung caáp tham soá cho $parameter2 thì tham soá naøy coù giaù trò laø 10. Ví duï, baïn khai baùo trang function.php coù haøm getResult nhaän hai soá vaø pheùp toaùn sau ñoù tuyø thuoäc vaøo pheùp toaùn haøm traû veà keát quaû. Neáu ngöôøi söû duïng khoâng cung vaáp pheùp toaùn thì maëc ñònh laø pheùp toaùn +. ::Welcome to PHP Function

Neáu muoán ñònh nghóa function khoâng coù giaù trò traû veà, baïn coù theå khai baùo trong trang void.php nhö ví duï sau:
... function calloperator() { echo "result of default operator: ".getResult(10,20); echo ""; echo "result of * operator: ".getResult(10,20,"*"); } calloperator(); ?>

Trong tröôøng hôïp truyeàn tham soá nhö tham bieán, baïn söû duïng kyù hieäu & tröôùc tham soá, chaúng haïn chuùng ta khai baùo haøm coù tham bieán coù teân average nhö trong trang reference.php nhö sau: ::Welcome to PHP Function

echo "result of Average is : ".$bq; echo ""; function getAmounts($quantity, $price,$average) { $result=0; $result=$quantity*$price; $average=$result*6/12; return $result; } $bq=0; echo "result is : ".getAmounts(10,20,$bq); echo ""; echo "result of Average is : ".$bq;

Trong tröôøng hôïp treân thì haøm getAmount coù tham soá $average laø tham bieán coøn haøm getAmounts coù tham soá $average laø tham trò, vaø keát quaû traû veà cuûa bieán $bq khi goïi haøm getAmount laø 100 trong khi ñoù giaù trò cuûa bieán naøy trong haøm getAmounts laø 0.

2. XAÂY DÖÏNG TAÄP TIN ÑÒNH DAÏNG NOÄI DUNG
Khi trình baøy noäi dung treân trang HTML hay trang PHP, ñeå thoáng nhaát ñònh daïng chuoãi trong theû body hay theû div chaúng haïn baïn caàn khai baùo theû style trong theû . A{ COLOR: #003063; TEXT-DECORATION: none } A:hover { COLOR: #003063; TEXT-DECORATION: underline } A:link { FONT-WEIGHT: bold; COLOR: red; TEXT-DECORATION: none } A:visited { FONT-WEIGHT: bold; COLOR: black; TEXT-DECORATION: none } .title { FONT-WEIGHT: normal; FONT-SIZE: 22px } .text{ FONT: 11px Arial, Helvetica, sans-serif }

Trong ñoù, A töông öùng vôùi lieân keát (chuoãi trong theû ) coù ñònh daïng öùng vôùi tröôøng hôïp lieân keát, di chuyeån con chuoät, choïn lieân keát.
A{ COLOR: #003063; TEXT-DECORATION: none } A:hover {

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} A:link { FONT-WEIGHT: bold; COLOR: red; TEXT-DECORATION: none } A:visited { FONT-WEIGHT: bold; COLOR: black; TEXT-DECORATION: none }

Chaúng haïn, chuùng ta khai baùo trang PHP vôùi noäi dung ñöôïc aùp duïng vôùi kieåu ñònh daïng khai baùo trong theû style nhö vuù duï 6-1. Ví duï 6-1: Khai baùo theû style Style trong PHP A{ COLOR: #003063; TEXT-DECORATION: none } A:hover { COLOR: #003063; TEXT-DECORATION: underline } A:link { FONT-WEIGHT: bold; COLOR: red; TEXT-DECORATION: none } A:visited { FONT-WEIGHT: bold; COLOR: black; TEXT-DECORATION: none } .title { FONT-WEIGHT: normal; FONT-SIZE: 22px; COLOR: #003063; } .text{ FONT: 11px Arial, Helvetica, sans-serif } Style Tag *** Quaûn Trò SQL Server 2000 *** Tìm hieåu caùch caøi ñaët, caáu hình, quaûn trò, backup & restore, import & export, thieát

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keá, laäp trình, töï ñoäng hoaù taùc vuï quaûn trò, baûn sao döõ lieäu, baûo maät vaø choáng thaâm nhaäp döõ lieäu baèng. SQL Injection.

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Trong ñoù trang templates.PHP khai baùo cheøn top.htm, left.htm, right.htm vaø bottom.htm nhö ví duï 6-5. Ví duï 6-5: Khai baùo cheøn taäp tin trong templates.php Welcome to HUUKHANG.COM

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