...Global Variables Global variables are used in applications in programming. There are advantages and disadvantages to using these variables. Using global variables has its advantages in some forms of applications, while using them in others would make using them more difficult. Global variables are useful when you need to share a function with all functions in an application. Global variables can be easier to identify in an application by giving them a unique name, so that other programmers can see they are working with a global variable when maintaining your application. On small programs such as widgets or gadgets it may be easier to use global rather than passing around local variables. Using a global variable means that other functions cannot update it. Another advantage to global is that they can be accessed from anywhere in the program. Some are also disadvantages to using global variables. Global variables can create mutual dependencies, with an increase in dependencies the complexity of the code increases. Any function can access a global variable in the program so a change in the program at one point can change values everywhere. Global variable also slow down performance speed a little. Using global variables makes reusing parts of the script impossible. Global variables also make tracking a bug much harder. When declaring a global variable in a flowchart, you would but the variable in the main part of the program, hence the box the other functions branch off of...
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...1 IS 247, Spring 2011, Coding Guidelines & Pair Programming • Suggestion: start homeworks early and send e-mail if you get stuck. Cell phones & laptops off. Reminder: if printing the notes, consider printing 4-up (4 pages per side) or 2-up or 6-up or some such. Generated 2015-01-26, 08:25:40 2 Java Operators ++ -~ ! * + / % > >>> = > < >= >> 1; b = b >>> 1; } // while something’s nonzero return count; } // hammingDistance() public static void main(String[] args) { System.out.println( hammingDistance(Integer.parseInt(args[0]), Integer.parseInt(args[1]))); } // main() } // class HammingDistance 4 A Refinement That version of Hamming Distance was fine, but can we take advantage of the fact the exclusive-or can be thought of as a not equals function? So if we take the exclusive-or of two integers, the result has a one in every bit position in which the numbers differ, and zeroes everywhere else. public static int hammingDistance(int a, int b) { int count = 0; // bits has a one wherever a and b differ int bits = a ^ b; while (bits != 0) { if ((bits & 1) == 1) // is the low bit one? ++count; bits = bits >>> 1; // done w/this bit } // while something’s nonzero return count; } // hammingDistance() This simplified the loop condition and took one shift out of the loop body. 5 Hamming Distance—Final Version It turns out we can simplify things a bit more through the use of the Java library. public static int hammingDistance(int...
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...block is a set of statements that belong together as a group, and are performed any time the function is executed. When a function is executing, what happens when the end of the function block is reached?When a function is executing, it 'returns' when the end of the block is reached - meaning the interpreter jumps back to the part of the program that called the function, and the program resumes execution at that point. What is a local variable? What statements are able to access a local variable?A local variable is a variable that is declared inside of a function. Only statements in the same function can access a local variable. What is a local variable's scope?A local variable's scope is the part of a program in which the variable may be accessed and is only visible to the statements in the variable's scope. Why do global variables make a program difficult to debug?Global variables make a program difficult to debug because any statement in a program file can change the value of a global variable. If you find that the wrong value is being stored in a global variable, you have to track down every statement that accesses it to determine where the bad value is coming...
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...Using Global Variables Global Variables Global variables are used in applications in programming. There are advantages and disadvantages to using these variables. Using global variables has its advantages in some forms of applications, while using them in others would make using them more difficult. Global variables are useful when you need to share a function with all functions in an application. Global variables can be easier to identify in an application by giving them a unique name, so that other programmers can see they are working with a global variable when maintaining your application. On small programs such as widgets or gadgets it may be easier to use global rather than passing around local variables. Using a global variable means that other functions cannot update it. Another advantage to global is that they can be accessed from anywhere in the program. Some are also disadvantages to using global variables. Global variables can create mutual dependencies, with an increase in dependencies the complexity of the code increases. Any function can access a global variable in the program so a change in the program at one point can change values everywhere. Global variable also slow down performance speed a little. Using global variables makes reusing parts of the script impossible. Global variables also make tracking a bug much harder. When declaring a global variable in a flowchart, you would but the variable in the main part of the program, hence the box the...
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...Derek Taylor 24 July 2015 Homework Assignment & Research Assignment 1.) What is the difference between Application Software and System Software? (Give an example of both) System software is an integral part that aids in the computer’s functioning. It manages the computer resources in ways that they can operate in tandem. System software provides a platform for the execution of application software. Examples of system software are BIOS and firmware. Application software is created for users. They manage their specific tasks to suit their needs like a media player of word processors. Examples of application software are CRM software, ERP software, accounting, graphics, and media software. 2.) What does it mean when we say that an interpreter both “Translates and Executes” Instructions? In the case of the interpreter, it translates and executes each line of codes one line at a time. Thus if the program has syntax errors (violation of program rule) lower down in the code, you never know until the interpreter reaches to that statement. 3.) Explain the “fectch-decode-execute” cycle. In the first step, fetch instruction, the processor fetches the instruction from the memory. The instruction is transferred from memory to instruction register. The processor is ready to fetch instruction. The instruction pointer contains the address 0100 contains the instruction MOV AX, 0. The memory places the instruction on the data bus. The processor then copies...
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...Appendix D: Answers to Checkpoint Questions Chapter 1 1.1 A program is a set of instructions that a computer follows to perform a task. 1.2 Hardware is all of the physical devices, or components, that a computer is made of. 1.3 The central processing unit (CPU), main memory, secondary storage devices, input devices, and output devices. 1.4 The CPU 1.5 Main memory 1.6 Secondary storage 1.7 Input device 1.8 Output device 1.9 One byte 1.10 A bit 1.11 The binary numbering system. 1.12 It is an encoding scheme that uses a set of 128 numeric codes to represent the English letters, various punctuation marks, and other characters. These numeric codes are used to store characters in a computer's memory. (ASCII stands for the American Standard Code for Information Interchange.) 1.13 Unicode 1.14 Digital data is data that is stored in binary, and a digital device is any device that works with binary data. 1.15 Machine language 1.16 Main memory, or RAM 1.17 The fetch-decode-execute cycle. 1.18 It is an alternative to machine language. Instead of using binary numbers for instructions, assembly language uses short words that are known as mnemonics. 1.19 A high-level language 1.20 Syntax 1.21 A compiler 1.22 An interpreter 1.23 A syntax error 1.24 The operating system 1.25 A utility program 1.26 Application software Chapter 2 2.1 Any person, group, or organization that is asking you to write a program. 2.2 A single function that the program...
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...Oracle9i: Program with PL/SQL Instructor Guide • Volume 2 40054GC11 Production 1.1 October 2001 D34008 Authors Nagavalli Pataballa Priya Nathan Copyright © Oracle Corporation, 1999, 2000, 2001. All rights reserved. This documentation contains proprietary information of Oracle Corporation. It is provided under a license agreement containing restrictions on use and disclosure and is also protected by copyright law. Reverse engineering of the software is prohibited. If this documentation is delivered to a U.S. Government Agency of the Department of Defense, then it is delivered with Restricted Rights and the following legend is applicable: Restricted Rights Legend Use, duplication or disclosure by the Government is subject to restrictions for commercial computer software and shall be deemed to be Restricted Rights software under Federal law, as set forth in subparagraph (c)(1)(ii) of DFARS 252.227-7013, Rights in Technical Data and Computer Software (October 1988). This material or any portion of it may not be copied in any form or by any means without the express prior written permission of Oracle Corporation. Any other copying is a violation of copyright law and may result in civil and/or criminal penalties. If this documentation is delivered to a U.S. Government Agency not within the Department of Defense, then it is delivered with “Restricted Rights,” as defined in FAR 52.227-14, Rights in Data-General, including Alternate III (June 1987). The information in this...
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...Disadvantages and Advantages of Using Global Variables The disadvantages of using global variables is that it has a lack of access control which can hinder security when working with 3rd party plug –ins. Global variables can have unlimited mutual dependencies which can make the program complexed according and integrating modules can also be difficult because other software written may use the same global variable names and your intentions were to use a local variable, creating name – space pollution. For example, if you are using a module and have to link it with another module, you will get linking errors because there are multiples of the same global name and it may not be thread safe. (Wiki.com). Global variables can be modified or read in any part of the program making it difficult to remember its use, according to Wiki.com/c2. The advantages of using global variables is that they are accessible anywhere in the program, they are declared at the beginning of the program by a global command and you can call them anywhere in the code. Use global variables in a public static field so it can be called anywhere in the programming and it will clog name space usage, (programmer.stachexchange.com). Common data can be declared global so you don’t have to use parameter passing. And because you can use it anywhere, use encapsulation to avoid corruption in the program, (yahoo.com). Global variables are in the assignment window while local variables are in the input box is how...
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...Unit 4 Research 1: Using Global Variables Advantages of using Global Variables * Global variable belongs to every function in the program. * Avoid passing frequently-used variables between several functions. * A global variable is accessible in every scope. * A global variable can potentially be modified from anywhere. * It can be accessed from any other files using extern. Disadvantages of using Global Variables * Non-locality -- Source code is easiest to understand when the scope of its individual elements is limited. Global variables can be read or modified by any part of the program, making it difficult to remember or reason about every possible use. * Implicit coupling -- A program with many global variables often has tight couplings between some of those variables, and couplings between variables and functions. Grouping coupled items into cohesive units usually leads to better programs. * Concurrency issues -- if globals can be accessed by multiple threads of execution, synchronization is necessary (and too-often neglected). When dynamically linking modules with globals, the composed system might not be thread-safe even if the two independent modules tested in dozens of different contexts were safe. * Namespace pollution -- Global names are available everywhere. You may unknowingly end up using a global when you think you are using a local (by misspelling or forgetting to declare the local) or vice versa. Also, if you ever have to link...
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...Mark Joren Crisologo 1BSCE-1 Basic Structures of C++ 1.Cin // i/o example #include <iostream> using namespace std; int main () { int i; cout << "Please enter an integer value: "; cin >> i; cout << "The value you entered is " << i; cout << " and its double is " << i*2 << ".\n"; return 0; } cin >> a >> b; | | 2.Cout cout << "Output sentence"; // prints Output sentence on screen cout << 120; // prints number 120 on screen cout << x; // prints the value of x on screen | | cout << "Hello"; // prints Hello cout << Hello; // prints the content of variable Hello | | cout << "First sentence.\n"; cout << "Second sentence.\nThird sentence."; | | 3. If statement if (x > 0.0) sum += x; if ( account_balance < 0 ) { cout << "Your account is overdrawn. Balance " << account_balance << endl; if ( overdraft_limit == 0 ) cout << "You have exceeded your limit. << endl; } if ( account_balance < 0 ) cout << "Your account is overdrawn. Balance " << account_balance << endl; if ( account_balance < 0 && overdraft_limit == 0 ) cout << "You have exceeded...
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...Unit 4 Homework 1. What are the five advantages and disadvantages of using global variables? Advantages * It is accessible to all modules in a program * You only have to declare it once outside the modules * It is good to use it for constants you want to keep consistent * It simplifies maintenance, avoids duplication of local constants * It can make a program easier to read in reference to constants Disadvantages * It makes debugging difficult * If modules use global variables it is dependent upon the module and if other modules are presented you have to redesign all over each time. * Any statement in a program can change the variable * It makes a program hard to understand since it can be modified and have to be aware of all other parts of the program that access it. * Global variables are not willing direct into flowcharts 2. How can you declare global and local variables in flowcharts? * Global variables are displayed in pseudo code but not in flowcharts directly In order to declare global variables in a flowchart, you’d put that variable in the main part of the program (the main box where other functions will branch off from) for local variables, you’d put those variables in the box where each separate functions executed. 3. What is the main difference between global and local variables? * A global variable applies to the entire application you are writing as for a local variable it could only apply for the section you are programming...
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...Denietra Franklin PT1420 Juan Hernandez 4/13/2015 Unit 4 Research Assignment 1. List 5 advantages and 5 disadvantages of using global variables. Advantages: 1.It is accessible to all the modules in a program. 2.You only have to declare it once outside the modules. 3.It is good to use it for constants you want to keep consistant. 4. It simplifies maintenance, avoids duplication of local constants. 5. It can make a program easier to read in reference to constants. Disadvantages: 1.It makes debugging difficult. 2.Any statement in a program can change the value. 3.If modules use global variables it is dependent upon the module and if other modules are presented you have to redesign all over each time. 4.It makes a program hard to understand since it can be modified and have to be aware of all other parts of the program that access it. 5.Global variables are not writing direct into flowcharts. 2. How can you declare global and local variables in flowcharts? Global variables are displayed in pseudocode but not in flowcharts directly. 3. How can you declare global and local variables in pseudocode? You can declare variables using the Global, Local, or Component statements, or you can use local variables without declaring them. Here are some examples: Local Number &AGE; Global String &OPER_NICKNAME; Component Rowset &MY_ROWSET; Local Any &SOME_FIELD; Local ApiObject &MYTREE; Local Boolean &Compare = True; Variable declarations...
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...1. Why is the “Scopes Monkey Trial” so historically significant? The Scopes Monkey Trial is historically significant because it is the first time that the creationist argument and the theory of evolution were debated within an education atmosphere. Also, it brought into question the legality of the government determining what can be taught in schools. 2. Why do you think the Supreme Court overturned the verdict on a technicality? I think the Supreme Court overturned the verdict on a technicality because the case was too controversial and divided people. So, the issue was not solved, but it was done before any further discussion on the matter could occur. So, the matter was overturned to avoid a public divide on the issue. 3. What are your...
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...In the movie “Inherit the Wind”, people made wrong choices, good choices, and no matter what they did someone had to suffer some consequences. But who really suffered the consequences in “Inherit the Wind”. I personally think that Bert Cates suffered the most. There are many reasons why and this essay will explain those reasons. When Bert’s girlfriend (Rachel Brown) goes up to the stand as a witness, Mr. Brady starts to pressure her. She seems to be holding back something that could be good evidence to the case. Mr. Brady starts yelling at her saying, “Tell us what you’re holding back! Tell us what you’re not saying! Say it! Say it! Say it!” She then starts to cry from the pressure. Had Bert not started talking about evolution...
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...The play Inherit the Wind by Jerome Lawrence and Robert E. Lee chronicles the trial of Bertram Cates—a school teacher in Tennessee who breaks the law by teaching Charles Darwin’s theory of evolution instead of creationism. Matthew Harrison Brady, the prosecuting attorney on the case, exhibits prominent characteristics which directly affects the way he conducts the trial. Brady displays various examples throughout the play of how his arrogance, insecurity, and intolerance influences the way he acts. To begin with, Matthew Harrison Brady’s arrogance is an aspect that altered his conduction of the trial. An example is when Brady learns Henry Drummond will be the defence attorney on the case. Regarding this piece of information, Brady says, “If the enemy sends its Goliath into battle, it magnifies our cause.” (pg. 25). Applause follows, and Brady basks in his egocentric glory. Never for a moment does he consider the possibility of his failure and instead believes having a worthy opponent will only make his victory more triumphant. This sense of excessive pride leaves Brady entering the trial unprepared for what follows. This is demonstrated later into the play when Drummond calls Brady to the witness stand as an expert on the bible. Brady agrees to this request and says, “‘If the interests of Right and Justice will be served, I will take the stand.’... (Brady moves to the witness stand in grandiose style).” (pg. 75-76). Brady is cocky and underestimates Drummond’s ability to navigate...
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