Programming techniques

Question 1

If loop

Answer 1

If the condition is true then one or two statements are execute
if condition is not true then statements under loop are skipped and then control is passed to the next statement

Question 2

Switch/end switch

Answer 2

can be used to compare multiple expressions

Question 3

Nested statement

Answer 3

Second statement is only checked if the first statement is true

Question 4

While/ end while loop

Answer 4

The condition is tested upon entry to the loop

Question 5

Do/until loop

Answer 5

The statements are executed before the condition is evaluated

Question 6

for/next loop

Answer 6

This is used to repeat a block of instructions a specified number of times

Question 7

What is modular programming?

Answer 7

This means breaking down a major task into smaller sub tasks

Question 8

Advantages of modular programming?

Answer 8

Programs can become easier to program and manage (once broken)
each module can be individually tested so it is easier to find errors
Modules can be re-used several times in a program
Much easier to de-bug and maintain

Question 9

Define a subroutine

Answer 9

A subroutine is a named block of code which performs a specific task within a program

Question 10

Define global variables

Answer 10

Global variables are variables used in the main program and these can be used anywhere in the program

Question 11

Define local variables

Answer 11

Local variables can be used within the subroutine and they only exist during the execution of the subroutine.They can not be accessed outside the subroutine and changing the value will have no effect.

Question 12

Define a Function

Answer 12

A subroutine with a named identifier called as a part of an expression.Returns multiple value or none
Function name(parameter)

Question 13

Define a Procedure

Answer 13

A subroutine with a named identifier can be called from anywhere in the program.when called code is executed and control passed back to the program where the procedure is called from
Returns a single value

Question 14

Define Iteration

Answer 14

Code that is executed a given number of times or until a condition is met.Can cause infinite loop if condition is not met

Question 15

Define Variables

Answer 15

Variables are identifier(names) given to memory locations whose contents will change during the course of the program

Question 16

Define a constant

Answer 16

Value that never changes while a program is being run

Question 17

One advantage of a constant

Answer 17

In a long complex program there is no chance that a programmer will accidentally change its value

Question 18

Define Sequence

Answer 18

A sequence is just two or more statements following one after the other

Question 19

Parameter passing by value

Answer 19

If a parameter is passed by value its actual value is passed to the subroutine,where it is treated as a local variable

Question 20

Parameter passing by reference

Answer 20

If a parameter is passed by reference the address and not the value of the parameter is passed to the subroutine

Question 21

Black box testing

Answer 21

Black box testing is carried out independently of the code used in the program

Question 22

What does black box testing do?

Answer 22

Looks at program specification
Creates a set of test data
Covers input,output and program functions

Question 23

What is white box testing?

Answer 23

White box testing is a method of testing software that tests the internal structure if workings of an application

Question 24

What is alpha testing?

Answer 24

This is carried out by the software developer’s in-house team and by the user

Question 25

What can alpha testing show?

Answer 25

It can reveal errors or omissions in the definition of the systems requirements.
The user may discover that the system does not do exactly what they wanted (often used by off-the-shelf software)

Question 26

what is beta testing?

Answer 26

This is used when commercial software is being developed e.g. windows
The software is given to a number of potential users who agree to use the software and report any faults.
Users may try to do things the developers don’t anticipate

Question 27

What is the water fall model and when to use?

Answer 27

Each stage is completed and documented before the next is begun. The customer only see the end product when its finished,any changes mean the project has to start over
when to use:
requirements are clear and fixed
short project
no ambiguous requirements

Question 28

Adv and Dis of waterfall model

Answer 28

Adv:
simple to use and understand
each stage is separate
makes project straightforward to manage
Dis:
not much user involvement after analysis stage
working software produced in last stages of cycle
to late to make changes have to start again

Question 29

What is the spiral model and when to use?

Answer 29

4 steps analysis,design ,implementation,evaluation
passes repeatedly through these steps.each loop generates a more refined prototype until requirements are met
When to use:
medium to high risk projects
requirements are complex
large projects with huge amount of time(maybe years)