### not()

#### Syntax

**not**(expression)

#### Description

Returns the logical Not of an *expression*.

All expressions in Omnis have a Boolean (truth) value. Firstly, non-zero numeric values (including negative values) are TRUE, zero values are FALSE. Secondly, string values are TRUE or FALSE depending on their numeric equivalent. String '1' has boolean value 1, therefore *not('1')* is 0. 'Bill' has boolean value 0, 'YES' has numeric value 0.

The numeric value of an expression that evaluates to true is 1, therefore *not(true) *is 0. Similarly, *not(false) *is 1.

You can also use **not()** to make method code more readable.

#### Example

###### Calculate lVar1 as not(2501)

###### ; returns 0

Calculate lVar1 as not('Hello there!')

###### ; is the same as not(0) which returns 1

Calculate lVar1 as not(31<45)

###### ; is the same as not(true) which returns false

Do method ProcessList Returns Done

###### If not(Done)

###### ; do something

###### End If

###### ; can be used to make code more readable