Javascript string comparison fails when comparing unicode characters

Question

I want to compare two strings in JavaScript that are the same, and yet the equality operator == returns false. One string contains a special character (eg. the

Answer 1

The JavaScript equality operator == will appear to be failing under the following circumstances. In all cases it is programmer error. Not a bug in JavaScript.

1. The two strings do not contain the same number and sequence of characters.

2. There is whitespace or newlines before, within or after one string. Use a trim() operator on both and look closely at both strings.

3. Surprise typecasting. The programmer is comparing datatypes that are incompatible.

4. There are unicode characters which look identical to other unicode characters but in fact are different unicode characters.