Pascal - Logical negation: not

The logical negation operator is used to determine the oposite value. in our case: if input is true then output is false, and if input is false the result is true. In next table you can find all possibilities:

a	x
False	True
True	False

information about the table: a is input, x is result

not

Description

not par1

Used keywords: not

Input

par1 - Logical value

Output

Result - Logical value

Compatible programing languages:
Object Pascal | Free Pascal

Examples

Pascal

In the source code you can find the equivalent of the above table, for easier orientation at the end of each line is a comment which shows the result.

a1 := not false; { a1 = true}
a2 := not true; { a2 = false}

Pascal

Even one example in what situations we can use the operation logical negation:

not a
not b and true
not(10 >a or a<5)

Pascal

Other pieces of example codes:

not a

repeat dec(i) until not i > 0;

repeat dec(i) until not i > 0;

You can find it in the following collections: logical operators

Logical negation in another programming language:

Differences to: