• Reference Guide

Is not Identical

x !== y
The operator compares the values x and y. If the both values are of different types or are not equal, the operator returns TRUE, otherwise FALSE. If the specified values are not of the same type, no conversion is performed and the operator returns TRUE immediately. If a comparison with conversion is desired, it is necessary to use the operator != instead.
[Int]0 != [Real]0
returns FALSE, because the first number is converted to a real number first, while
[Int]0 !== [Real]0
returns TRUE, because the numbers are of distinct types.