N5 Computing Science: Structure Charts

Which type of software design notation is shown here?

• Structure diagram

• Flow chart

• Pseudocode

• Program code

Answer explanation

At N5 level you need to be familiar with structure diagrams, flowcharts and pseudocode as design notations.

Match the structure diagram symbols to their meaning ...

• selection

• 
• process

• 
• loop

• 
• subroutine

• 

Answer explanation

Structure diagrams have their own set of symbols, some of which are similar to flowchart symbols.

How many levels of problem decomposition are shown in this diagram?

• 3

• 4

• 5

• None

Answer explanation

Decomposition refers to the repeated breaking up of a problem into smaller and smaller subproblems, until the subproblems are trivial to solve. This is also called stepwise refinement.

Which type of repetition is shown?

• Conditional loop

• Fixed loop over a range of integers

• Fixed loop over a data structure

Answer explanation

A fixed loop is a type of loop that repeats for a pre-determined number of times.

Draw a circle round the repetition part of the diagram ...

Answer explanation

Repetition is the repeating of blocks of code a number of times. This is also called looping or iteration.

Draw a circle round a selection part of the diagram ...

Answer explanation

Selection is when the program makes a decision between one or more alternative blocks of code. This is usually implemented by a 'if' block of code.

Type the name of a variable of type real/float ...

Answer explanation

Real (or float) variables can store numbers with fractional parts, such as 3.14.

Type the name of a variable of type integer ...

Answer explanation

Integers are positive or negative whole numbers (including zero.)

Type the name of a variable of type string ...

Answer explanation

Strings are sequences of ASCII characters, usually denoted by quotation symbols "" or ''.

How many selection statements are there?

Answer explanation

Selection statements are decisions and in structure diagrams are represented by the hexagonal shape.