2.2.1 Programming Techniques

Question 1

Sequence

Answer 1

Executing instructions one after another

Question 2

Selection (branching)

Answer 2

• IF statement
• A construct that allows a program to change direction depending on the outcome of a condition

Question 3

Iteration

Answer 3

Enables us to repeat sections of code

Question 4

When is a FOR loop (count-controlled loop) used?

Answer 4

When the required number of iterations is known ahead of the execution

Question 5

When is a WHILE loop (condition-controlled loop) used?

Answer 5

When the required number of iterations is unknown as the variable used to determine when the iteration ends is changing within the iteration itself

Question 6

Nest structure

Answer 6

Programming constructs inside one another

Question 7

Recursion

Answer 7

When a subroutine calls itself from within another subroutine

Question 8

What 3 characteristics should a recursion subroutine have?

Answer 8

• Contains a stopping condition (base case)
• For an input value other than the base case, the subroutine should call itself
• The stopping condition should be reachable within a finite number of times

Question 9

Without the 3 characteristics, what would the recursion subroutine result in?

Answer 9

A stack overflow

Question 10

Variable

Answer 10

Used to store information to be referenced and manipulated in a computer program

Question 11

Local variable (4)

Answer 11

• Declared inside a subroutine
• Only accessible by that subroutine
• Created when the subroutine is called
• Destroyed when the subroutine ends

Question 12

Global variable (4)

Answer 12

• Declared at the top of a program, outside of any subroutine
• Accessible throughout the program
• Created when the program starts
• Destroyed when the program ends

Question 13

Scope of a variable

Answer 13

• Refers to where the variable can be accessible in the code

Question 14

Procedure

Answer 14

• Block of code that takes in zero, one or more parameters and performs a set task

Question 15

Function

Answer 15

• Block of code that takes in zero, one or more parameters and performs a set task
• RETURNS A VALUE

Question 16

Modularity

Answer 16

Concept of breaking a large program into smaller chunks
- Each module carries out a single, specific task

Question 17

Integrated Development Environments

Answer 17

• Program that provides a set of tools and related functionality designed to maximise a programmer’s productivity

Question 18

Common features of IDEs

Answer 18

• Auto-documentation
• Syntax highlighting
• Error diagnostics
• Code editors
• Translators

Question 19

Code editor

Answer 19

A text area for programmers to enter code directly into the IDE; often supports features e.g. syntax highlighting, automatic indentation

Question 20

Error diagnostics

Answer 20

Reports errors in the code and where they can be found

Question 21

Translators

Answer 21

Program that converts high level code into machine code