Legal identifier matching regex pattern

The following will match any legal identifier — an unlimited-length sequence of Unicode letters and digits, beginning with a letter, the dollar sign "$", or the underscore character

/^[a-zA-Z\$_][a-zA-Z0-9]*/

The following is a example in Javascript


alert(/^[a-zA-Z\$_][a-zA-Z0-9]*/.test("testVar"));

Comments

Unknown said…

Small correction. This will not match any Unicode letters since you've specified a subset of ASCII :-)

February 3, 2010 at 2:46 AM

chanaka said…

Thanks Chintana for the correction.

To simplify and correct the regex it can be written as

/^[\w\$][\w]*/

Since Firefox regex engine doesn't know Unicode \w is equivalent to [a-zA-Z0-9_]

February 4, 2010 at 2:56 AM

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