Javascript: quick string test

Question

I wish to know how to test strings composed of certain string and characters. I've tested

/translate+x|y|z/i.test('translateX') returns true
/translate+x|y|z/i.test('translate') returns false
/translate+x|y|z/i.test('rotateX') returns false

So with other words, I need to know if the string is translateX or translateY or translateZ but I am not sure if I have / don't have to escape the + there. Also please DO suggest a better all round, cross-browser solution that can be shorter / more precise.

What are trying to achieve? What are the requirements? \+ matches a literal + and in your pattern, + is a quantifier allowing to match several e after translat. — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Mar 7, 2016 at 12:52
Thanks for the input, so I basically want to know if the string is translateX or translateY or translateZ in a very short and efficient .test() call. — thednp
– thednp, Commented Mar 7, 2016 at 12:59

Wiktor Stribiżew · Accepted Answer · 2016-03-07 13:32:53Z

1

I basically want to know if the string is translateX or translateY or translateZ in a very short and efficient .test() call.

You can use

/^translate[XYZ]$/

See the regex demo here.

The regex matches a string that is equal to translateX, translateY or translateZ.

^ - start of string
translate - a literal character sequence
[XYZ] - either X, Y or Z ([ ... ] a character class where the single characters alternatives are listed)
$ - end of string

If you need to add multicharacter alternatives, use alternation:

/^translate(?:[XYZ]|3d)$/
           ^^^     ^^^^

This regex will match those 3 strings as above, or translate3d.

edited Mar 7, 2016 at 13:32

answered Mar 7, 2016 at 13:04

Wiktor Stribiżew

631k41 gold badges502 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

thednp Over a year ago

Awesome, thank you for such a detailed answer/suggestion.

Wiktor Stribiżew Over a year ago

Glad it works for you. One note: if you need to make it case insensitive, add /i to the end: /^translate[XYZ]$/i.

thednp Over a year ago

Actually, how can I add 3d to the [XYZ] list?

Wiktor Stribiżew Over a year ago

Use alternation: /^translate(?:[XYZ]|3d)$/

thednp Over a year ago

Excellent, that worked perfect. I wish you were my friend forever :)

Collectives™ on Stack Overflow

Javascript: quick string test

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related