How can I check if the contents of a variable start with something?

Question

I would like to do something like this:

if (idCity == 'AB*') {
   //  do something
}

In other words. I want to check that idCity starts with the string "AB". How can I do this in Javascript?

See http://stackoverflow.com/questions/646628/javascript-startswith — Joachim Isaksson, Jan 08 '12 at 08:13
possible duplicate of [javascript - check if string begins with something?](http://stackoverflow.com/questions/1767246/javascript-check-if-string-begins-with-something) — Felix Kling, Jan 08 '12 at 09:10
How about reading through the [list of string manipulation methods](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String#Methods_unrelated_to_HTML) until you find one that seems to do the trick? — nnnnnn, Jan 08 '12 at 09:20

score 3 · Answer 1 · answered Jan 08 '12 at 08:08

3

if (idCity.substr(0,2) == 'AB') {
   alert('the string starts with AB');
}

answered Jan 08 '12 at 08:08

Marc B

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RiaD · Answer 2 · 2012-01-08T09:39:05.737

2

if(idCity.substr(0,2)=='AB'){
}

If 'AB' is not constant string, you may use

if(idCity.substr(0,start.length)==start){
}

edited Jan 08 '12 at 09:39

answered Jan 08 '12 at 08:09

RiaD

46,822
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`.length` is a property, not a method. – nnnnnn Jan 08 '12 at 09:19

score 2 · Answer 3 · answered Jan 08 '12 at 08:12

2

if(idCity.indexOf('AB') == 0)
{
  alert('the string starts with AB');
}

answered Jan 08 '12 at 08:12

Joachim Isaksson

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score 0 · Answer 4 · answered Jan 08 '12 at 08:11

0

idCity = 'AB767 something';

function startWith(searchString){
    if (idCity.indexOf(searchString) == 0){
         return true;
    }
    return false;
}

answered Jan 08 '12 at 08:11

mohdajami

9,604
3
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53

just `return idCity.indexOf(searchString) == 0` seems to be much simpler – RiaD Jan 08 '12 at 10:16

How can I check if the contents of a variable start with something?

4 Answers4