---
layout: page
title: "JavaScript array_keys function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/array_keys:324
- /functions/view/array_keys
- /functions/view/324
- /functions/array_keys:324
- /functions/324
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's array_keys

{% codeblock array/array_keys.js lang:js https://raw.github.com/kvz/phpjs/master/functions/array/array_keys.js raw on github %}
function array_keys (input, search_value, argStrict) {
  // From: http://phpjs.org/functions
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +      input by: Brett Zamir (http://brett-zamir.me)
  // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: jd
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // +   input by: P
  // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: array_keys( {firstname: 'Kevin', surname: 'van Zonneveld'} );
  // *     returns 1: {0: 'firstname', 1: 'surname'}

  var search = typeof search_value !== 'undefined',
    tmp_arr = [],
    strict = !!argStrict,
    include = true,
    key = '';

  if (input && typeof input === 'object' && input.change_key_case) { // Duck-type check for our own array()-created PHPJS_Array
    return input.keys(search_value, argStrict);
  }

  for (key in input) {
    if (input.hasOwnProperty(key)) {
      include = true;
      if (search) {
        if (strict && input[key] !== search_value) {
          include = false;
        }
        else if (input[key] != search_value) {
          include = false;
        }
      }

      if (include) {
        tmp_arr[tmp_arr.length] = key;
      }
    }
  }

  return tmp_arr;
}
{% endcodeblock %}

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

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

Should return
{% codeblock lang:js returns %}
{0: 'firstname', 1: 'surname'}
{% endcodeblock %}


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