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Computer Science IGCSEPDF 100
142 pagesrevision 46930
PDF 100
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● Text should be evenly spaced with a consistent size throughout.
● Lines should be indented (usually by three spaces) to indicate that they are
contained within a statement in a previous
line.
● Keywords should be in uppercase, e.g. REPEAT,ELSE, etc.
● Comments should be included and are compulsory for the last question.
○ Comments are started by “//”.
○ They are usually on an independent line.
○ Smaller comments may be on the same line as the code they refer to.
● Identifiers:
○ They should describe the variable, constant, procedure or function they
represent.
○ They can be in mixed case
○ They should be considered case insensitive, i.e. you cannot create a
different identifier by changing the case of the original identifier.
○ They can only contain letters (A–Z, a–z), digits (0–9) and the underscore
character ( _ ).
○ They must start with a letter and not a digit.
8.1.1 Data Types
DataType
Explanation
Example
INTEGER
A whole number
67,526
REAL
A number containing a fractional part
42.6,-8.0
CHAR
A single character
‘x’,’#’
STRING
A sequence of characters
“Hello world”
BOOLEAN
The values TRUE and FALSE
TRUE ; FALSE