Logical NOT Operator (!)

  • Article

Performs logical negation on an expression.

result = !expression

Arguments

  • result
    Any variable.
  • expression
    Any expression.

Remarks

The following table illustrates how result is determined.

If expression is Then result is
True False
False True

All unary operators, such as the ! operator, evaluate expressions as follows:

  • If applied to undefined or null expressions, a run-time error is raised.
  • Objects are converted to strings.
  • Strings are converted to numbers if possible. If not, a run-time error is raised.
  • Boolean values are treated as numbers (0 if false, 1 if true).

The operator is applied to the resulting number.

For the ! operator, if expression is nonzero, result is zero. If expression is zero, result is 1.

Requirements

Version 1

See Also

~ Operator | Operator Precedence | Operator Summary