Department of Engineering

University of Cambridge >  Engineering Department >  computing help

Expressions

Expressions are used to compute values by applying operators to variables, constants and literal values. The operators for the predefined types include:

integer ops	+, -, *, /, % (modulus)	e.g. (13+4)/5 is 3
real ops	+, -, *, /	e.g. (13.0+4.0)/5.0 is 3.4
relational ops	==, !=, >=, <=, >, <	e.g. (6+2)<9 is true
logical ops	&& (and), || (or), ! (not)	e.g. (6>8) || (3<4) is true
bit-shift ops	>>, <<	e.g. 2<<10 is 2048

Precedence order:

1.

!, not (logical not)

2.

*, /, %

3.

+, -

4.

>>, <<

5.

<, <=, >, >=

6.

==, !=

7.

&&, and (logical and)

8.

||, or (logical or)

Increment and decrement operators (see section 8 on assignment statements):

• count++ is equivalent to count = count + 1;
• count-- is equivalent to count = count - 1;

 Operators can be defined for user types. See the use of << and >> in section 11, and the -- member function in the example class in section 18.

| computing help |

© Cambridge University Engineering Dept
Information provided by Tim Love
2006-12-08