In JS, how do I determine if a string is contained within another string?

Question

In Javascript, how do I determine if some specific HTML is contained within a larger hunk of HTML?

I tried regex:

var htmlstr;
var reg = /<b class="fl_r">Example</b>/.test(htmlstr);

but it doesn't work! Console outputs "missing /". Please, help me fix this.

Please no.... [NOOOOOOOooooooooo](http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454) — Chase Florell, Jul 02 '11 at 01:53
So, is there any other way to see if this string contains that substring?? — DrStrangeLove, Jul 02 '11 at 01:56
are you trying to get "Example" from within an element with a class of `fl_r`? — Chase Florell, Jul 02 '11 at 02:01
@rockinthesixstring, there may be more than one "Example" on the page. i need exactly this "Example" -surrounded with and — DrStrangeLove, Jul 02 '11 at 02:35
@rockinthesixstring, another question - in case of xhtml, in general, should i parse it as html or as xml?? — DrStrangeLove, Jul 02 '11 at 02:37

Chandu · Answer 1 · 2011-07-02T02:05:52.703

2

You need to escape the / character.

Try:

var htmlstr = '<b class="fl_r">Example</b>';
var reg =  /<b class="fl_r">Example<\/b>/.test(htmlstr);

Example @ http://jsfiddle.net/7cuKe/2/

edited Jul 02 '11 at 02:05

answered Jul 02 '11 at 01:54

Chandu

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it worked the first time. but after i assigned Example to htmlstr, it doesnt work anymore! (i anticipated 'true') :( – DrStrangeLove Jul 02 '11 at 02:04
@Dr: Updated the post. Pls check – Chandu Jul 02 '11 at 02:06

score 2 · Accepted Answer · answered Jul 02 '11 at 02:05

Regex is a bit of an overkill here. You can just use indexOf like this and not have to worry about escaping things in the string:

var htmlstr1 = 'foo';
var htmlstr2 = 'some stuff <b class="fl_r">Example</b> more stuff';

if (htmlstr1.indexOf('<b class="fl_r">Example</b>') != -1) {
    alert("found match in htmlstr1");
}

if (htmlstr2.indexOf('<b class="fl_r">Example</b>') != -1) {
    alert("found match in htmlstr2");
}

jsFiddle to play with it is here: http://jsfiddle.net/jfriend00/86Kny/

In JS, how do I determine if a string is contained within another string?

2 Answers2