# Metadata
Platforms: desktop, server, mobile OS: mac, windows, linux, ios, android Introduced: 1.0 Security:
# Syntax
value is not a[n] {boolean | integer | number | point | rect| date | color | ASCII string}
# Params
- value : Any source of value.
# Examples
22 is not a number
CJ22 is not a number
numToChar(128) is not an ASCII string -- evaluates to true
# Description
This operator is useful for checking whether the user has entered data correctly, and for checking parameters before sending them to a handler to avoid a script error caused by feeding data of one type to an operator or function that requires a different type.
A value is a:
* boolean or logical if it is one of the two constants true or false
* integer if it consists of digits (with an optional minus sign)
* number if it consists of digits, optional leading minus sign, optional decimal point, and optional "E" or "e" (scientific notation)
* point if it consists of two numbers separated by a comma
* rect if it consists of four numbers separated by commas
* date if it is in one of the formats produced by the date or time functions
* color if it is a valid color reference
* ASCII string if it does not contain any characters greater than charToNum(127)
All the types other than boolean can also include leading or trailing white space characters.
The is not a operator is the logical inverse of the is a operator. When one is true, the other is false.
# Tags
math,
# See