Microsoft® JScript ! Operator |
Language Reference |
Used to perform logical negation on an expression.
result = !expressionThe ! operator syntax has these parts:
Part Description result Any variable. expression Any expression.
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:For the ! operator, if expression is nonzero, result is zero. If expression is zero, result is 1.
- 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.
- Booleans are treated as numbers (0 if false, 1 if true).
- The operator is applied to the resulting number.