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

php.js offers community built php functions in javascript

---
layout: page
title: "JavaScript array_flip function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/array_flip:317
- /functions/view/array_flip
- /functions/view/317
- /functions/array_flip:317
- /functions/317
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's array_flip

{% codeblock array/array_flip.js lang:js https://raw.github.com/kvz/phpjs/master/functions/array/array_flip.js raw on github %}
function array_flip (trans) {
  // From: http://phpjs.org/functions
  // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: Pier Paolo Ramon (http://www.mastersoup.com/)
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // -    depends on: array
  // *          test: skip
  // *     example 1: array_flip( {a: 1, b: 1, c: 2} );
  // *     returns 1: {1: 'b', 2: 'c'}
  // *     example 2: ini_set('phpjs.return_phpjs_arrays', 'on');
  // *     example 2: array_flip(array({a: 0}, {b: 1}, {c: 2}))[1];
  // *     returns 2: 'b'

  var key, tmp_ar = {};

  // Duck-type check for our own array()-created PHPJS_Array
  if (trans && typeof trans === 'object' && trans.change_key_case) {
    return trans.flip();
  }

  for (key in trans) {
    if (!trans.hasOwnProperty(key)) {
      continue;
    }
    tmp_ar[trans[key]] = key;
  }

  return tmp_ar;
}
{% endcodeblock %}

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

### Example 1
This code
{% codeblock lang:js example %}
array_flip( {a: 1, b: 1, c: 2} );
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
{1: 'b', 2: 'c'}
{% endcodeblock %}

### Example 2
This code
{% codeblock lang:js example %}
ini_set('phpjs.return_phpjs_arrays', 'on');
array_flip(array({a: 0}, {b: 1}, {c: 2}))[1];
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
'b'
{% endcodeblock %}


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