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 the instruction from the data bus to the instruction register. In the second step, decode instruction, the instruction is decoded by the processor. For example, the instruction MOV AX, 0. Stores the value 0 in Ax register. The processor will fetch the constant value 0 from the next location in memory before executing the instruction. The processor gets any operand if required by the instruction. Last step, execute instruction, the processor execute the instruction, it stores 0 in register AX.

4.) Which program will usually execute faster, a compiled program or an interpreted program? Compiled programs generally run faster than interpreted ones because interpreted programs must be reduced to machine instructions at runtime. However, with an interpreted language you can do things that cannot be done in a compiled language. For example, interpreted programs can modify themselves by adding or changing functions at runtime.
5.) Give an example of a machine language instruction.

6.) Explain the difference between logic error and syntax error?

A Syntax Error occurs when the code isn't formatted or typed correctly. i.e. In python, typing If instead of if because it only recognizes lowercase.

A logical error occurs when there is a fallacy of reasoning. i.e. In python, typing if x < 0 and x > 5. Since a value can't be less than 0 and greater than 5, a logical error will occur.

7.) List five steps of the program development cycle.

1.Review the input, processing, output, and storage requirements.
2.Develop the logic for the program
3.Write the program using a programming language.
4.Test and debug the program.
5.Complete the program documentation.

8.) How is a “processing symbol” used in a flowchart?

It represents any process, function, or action and is the most frequently used symbol in flowcharting.

9.) Explain the “Order of Operations” in solving an equation?
This is a rule that defines which procedures to perform first in a given mathematical expression. For example, in mathematics and most computer languages, multiplication precedes addition. Thus, in the expression 2 + 3 × 4, the answer is 14 (not 20). Brackets,( and ), { and }, or [ and ]—which have their own rules—can indicate an alternate order or reinforce the default order to avoid confusion, thus the preceding expression could be changed to (2 + 3) × 4 to produce 20, or 2 + (3 × 4) to produce 14 (the default if there are no brackets).
10.) List three variable types used in pseudocode? Do not confuse with variables in visualbe basic. declare integer i declare constant permanent integer j

11.) Use the correct symbol to write the state “two raised to the power of 6”

2^6 or 26

12.) List three benefits of using modules (or subroutines)?

Benefits of subroutines;

Decomposing a complex programming task into simpler steps: this is one of the two main tools of structured programming, along with data structures
Reducing duplicate code within a program
Enabling reuse of code across multiple programs
Benefits of Modules;

Fewer bugs because each set of programming commands is shorter

Algorithm is more easily understood

Many programmers can be employed, one on each of the modules

13.) What is the difference in passing a value to a subroutine ByVal or ByRef?

If you pass in a reference, when you modify the value in the method, the variable in the call site will also be modified.
If you pass value, it's the same as if another variable is created at the method, so even if you modify it, the original variable (at the call site) won't have its value changed.
14.) Explain the difference between a global variable and a local variable?
Global variables can be accessed from anywhere in a program, so variables that do not change are generally global in scope. A program that relies on a value of pi, for example, might use a global variable. They are often placed at the beginning of a program where they are easy to access, and constant global variables are often spelled with all capital letters.
Local variables, on the other hand, are typically used in a single function or method. This allows programmers to reuse variable names. The variable "i" is often used for iteration, and making it local allows it to be used whenever necessary.
Experts strongly recommend using global variables only when necessary.
15.) As defined by your textbook in Unit 2, what are the normal rules for variable names? Variable names in Visual C++ can range from 1 to 255 characters. To make variable names portable to other environments stay within a 1 to 31 character range. All variable names must begin with a letter of the alphabet or an underscore( _ ). After the first initial letter, variable names can also contain letters and numbers. No spaces or special characters, however, are allowed. Uppercase characters are distinct from lowercase characters. Using all uppercase letters is used primarily to identify constant variables. You cannot use a C++ keyword (reserved word) as a variable name. NEVER use uppercase for every letter in a variable name, because uppercase names are reserved for constant variables.
16. What is the effect of the NOT operator?

If logical NOT’s operand evaluates to true, logical NOT evaluates to false. If logical NOT’s operand evaluates to false, logical NOT evaluates to true. In other words, logical NOT flips a boolean value from true to false, and vice-versa.

17.) What is the effect of using the AND operator?

The logical AND operator is used to test whether both conditions are true. If both conditions are true, logical AND returns true. Otherwise, it returns false.

18.) What is the effect of using the OR operator?

The logical OR operator is used to test whether either of two conditions is true. If the left operand evaluates to true, or the right operand evaluates to true, the logical OR operator returns true. If both operands are true, then logical OR will return true as well.

Definitions:

Syntax - the rules that must be followed when writing a program

Mnemonics - is a term, symbol or name used to define or specify a computing function. Mnemonics are used in computing to provide users with a means to quickly access a function, service or process, bypassing the actual more lengthy method used to perform or achieve it.

FORTRAN - is a general-purpose, imperative programming language that is especially suited to numeric computation and scientific computing. Originally developed by IBM[1] in the 1950s for scientific and engineering applications.

Two’s Compliment - is a mathematical operation on binary numbers, as well as a binary signed number representation based on this operation. Its wide use in computing makes it the most important example of a radix complement.

Pseudocode - is an informal high-level description of the operating principle of a computer program or other algorithm.

Flowchart - is a diagrammatic representation of an algorithm. Flowchart are very helpful in writing program and explaining program to others.

Sequence Structure - an action, or event, leads to the next ordered action in a predetermined order. The sequence can contain any number of actions, but no actions can be skipped in the sequence. The program, when run, must perform each action in order with no possibility of skipping an action or branching off to another action.

Control Structure - is a block of programming that analyzes variablesand chooses a direction in which to go based on given parameters.

Named Constant – is a name that represents a value that cannot be changed during the program’s execution.

Return Point - After finishing a subroutine, the program will branch back (return) to the point after the call.

Parameter - a special kind of variable, used in a subroutine to refer to one of the pieces of data provided as input to the subroutine.

Hierarchy Charts - Conveys the relationship or big picture of the various functions in a program.

Relational Operator - is a programming language construct or operator that tests or defines some kind of relation between two entities. These include numerical equality (e.g., 5 = 5) and inequalities (e.g., 4 ≥ 3).

Variable - is a storage location paired with an associated symbolic name (an identifier), which contains some known or unknown quantity of information referred to as a value.

Algorithm - are the set of well defined instruction in sequence to solve a program. An algorithm should always have a clear stopping point.

Flowchart Symbols

Rectangle - This shape is used to show that something is performed.

Diamond – shows where a decision is necessary, commonly a Yes/No question or True/False test.

Oval - usually contain the word "Start" or "End", or another phrase signaling the start or end of a process, such as "submit inquiry" or "receive product".

Parallelogram - Input/Output. Examples; Get X from the user; display X.

Coding Symbols

* - greater than

< - Less than

>= greater than or equal to the value

<= less than or equal to the value

== Equal to

!= Not equal to

What is the difference between using “=” and using “==”?

“=” is direct assignment

“==” is equal to