phpjs/_octopress/source/functions/substr_count/index.markdown

php.js offers community built php functions in javascript

---
layout: page
title: "JavaScript substr_count function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/substr_count:559
- /functions/view/substr_count
- /functions/view/559
- /functions/substr_count:559
- /functions/559
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's substr_count

{% codeblock strings/substr_count.js lang:js https://raw.github.com/kvz/phpjs/master/functions/strings/substr_count.js raw on github %}
function substr_count (haystack, needle, offset, length) {
  // From: http://phpjs.org/functions
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   bugfixed by: Onno Marsman
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // +   improved by: Thomas
  // *     example 1: substr_count('Kevin van Zonneveld', 'e');
  // *     returns 1: 3
  // *     example 2: substr_count('Kevin van Zonneveld', 'K', 1);
  // *     returns 2: 0
  // *     example 3: substr_count('Kevin van Zonneveld', 'Z', 0, 10);
  // *     returns 3: false

  var cnt = 0;

  haystack += '';
  needle += '';
  if (isNaN(offset)) {
    offset = 0;
  }
  if (isNaN(length)) {
    length = 0;
  }
  if (needle.length == 0) {
    return false;
  }
  offset--;

  while ((offset = haystack.indexOf(needle, offset + 1)) != -1) {
    if (length > 0 && (offset + needle.length) > length) {
      return false;
    }
    cnt++;
  }

  return cnt;
}
{% endcodeblock %}

 - [Raw function on GitHub](https://github.com/kvz/phpjs/blob/master/functions/strings/substr_count.js)

Please note that php.js uses JavaScript objects as substitutes for PHP arrays, they are 
the closest match to this hashtable-like data structure. 

Please also note that php.js offers community built functions and goes by the 
[McDonald's Theory](https://medium.com/what-i-learned-building/9216e1c9da7d). We'll put online 
functions that are far from perfect, in the hopes to spark better contributions. 
Do you have one? Then please just: 

 - [Edit on GitHub](https://github.com/kvz/phpjs/edit/master/functions/strings/substr_count.js)

### Example 1
This code
{% codeblock lang:js example %}
substr_count('Kevin van Zonneveld', 'e');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
3
{% endcodeblock %}

### Example 2
This code
{% codeblock lang:js example %}
substr_count('Kevin van Zonneveld', 'K', 1);
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
0
{% endcodeblock %}

### Example 3
This code
{% codeblock lang:js example %}
substr_count('Kevin van Zonneveld', 'Z', 0, 10);
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
false
{% endcodeblock %}


### Other PHP functions in the strings extension
{% render_partial _includes/custom/strings.html %}