---
layout: page
title: "JavaScript in_array function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/in_array:432
- /functions/view/in_array
- /functions/view/432
- /functions/in_array:432
- /functions/432
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's in_array

{% codeblock array/in_array.js lang:js https://raw.github.com/kvz/phpjs/master/functions/array/in_array.js raw on github %}
function in_array (needle, haystack, argStrict) {
  // From: http://phpjs.org/functions
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: vlado houba
  // +   input by: Billy
  // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: in_array('van', ['Kevin', 'van', 'Zonneveld']);
  // *     returns 1: true
  // *     example 2: in_array('vlado', {0: 'Kevin', vlado: 'van', 1: 'Zonneveld'});
  // *     returns 2: false
  // *     example 3: in_array(1, ['1', '2', '3']);
  // *     returns 3: true
  // *     example 3: in_array(1, ['1', '2', '3'], false);
  // *     returns 3: true
  // *     example 4: in_array(1, ['1', '2', '3'], true);
  // *     returns 4: false
  var key = '',
    strict = !! argStrict;

  if (strict) {
    for (key in haystack) {
      if (haystack[key] === needle) {
        return true;
      }
    }
  } else {
    for (key in haystack) {
      if (haystack[key] == needle) {
        return true;
      }
    }
  }

  return false;
}
{% endcodeblock %}

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

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

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

### Example 2
This code
{% codeblock lang:js example %}
in_array('vlado', {0: 'Kevin', vlado: 'van', 1: 'Zonneveld'});
{% endcodeblock %}

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

### Example 3
This code
{% codeblock lang:js example %}
in_array(1, ['1', '2', '3']);
in_array(1, ['1', '2', '3'], false);
{% endcodeblock %}

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


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