how to find the number of occurences of a substring in a string in javascript?

Question

I have the following code in javascript.

    var contents = '<p>this is some text.<span class="Am"></span>This is som text<span class="Am"></span>This is some text<span class="Am"></span></p>';

Now I have to find the number of occurences of span tag inside this string and then use a loop throgh this number. For example

 function doStuff(){
        var contents = '<p>this is some text.<span class="Am"></span>This is som text<span class="Am"></span>This is some text<span class="Am"></span></p>';
        var spans = 'Number of spans in the string';  // this is required to me
        for(i=1;i<=spans;i++){
            // do some stuff
            }
       }

Can anyone tell me how it can be done with javascript ?

Thanks in advance.

THis will help you - http://stackoverflow.com/questions/4009756/how-to-count-string-occurrence-in-string — MusicLovingIndianGirl, Jan 02 '14 at 11:51

score 3 · Answer 1 · answered Jan 02 '14 at 11:52

3

One way:

var temp = document.createElement("DIV");
temp.innerHTML = contents;

var count = temp.getElementsByTagName("SPAN").length;

answered Jan 02 '14 at 11:52

Alex K.

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+1 for letting the browser decide. A quite better (and more flexible) way to accomplish the desired. – Roko C. Buljan Jan 02 '14 at 12:29
And what if it is not meant for a browser? – Alex Oct 09 '17 at 17:52

Mehran Hatami · Accepted Answer · 2014-01-02T12:14:10.903

2

try this, its pretty hardcode but works:

contents.split("</span>").length - 1

you can also try this:

contents.match(/<span/ig).length

edited Jan 02 '14 at 12:14

answered Jan 02 '14 at 11:53

Mehran Hatami

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@user2826169 also if you need to take care for `span` and `SPAN` aswell the *insensitive global* `ig` flag might help. – Roko C. Buljan Jan 02 '14 at 12:12

Rob Sedgwick · Answer 3 · 2014-01-02T12:22:57.987

dam, folks are quick at answering : ) ...

Here is a reusable way to throw in the mix

    /* function stringmatchCount(str,instr) {
       var count = instr.match(/str/g);
       return count.length;
     } */

*UPDATE AS ROKO better shows

  function stringmatchCount(str,dlm) {
       var d = new RegExp(dlm, "g");
        return str.match(d).length;
     }

usage, like in your example.

 function doStuff(){
   var contents = '<p><span class="Am"></span>doo, daaa<span></span>';
   var spans = stringmatchCount(contents,'<span');
    for (var i = 0, len=spans; i < len; ++i) {
     ... 
     }
  }

score 0 · Answer 4 · answered Jan 02 '14 at 11:51

0

Try this code :-

contents.match(/\<span\>//g).length

answered Jan 02 '14 at 11:51

Durgaprasad Budhwani

977
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how to find the number of occurences of a substring in a string in javascript?

4 Answers4