Arrays with unique entries

From MapbenderWiki

The goal is to delete multiple occurences of an item in an array.

Example:

[0] => 1
[1] => 2
[2] => 1
[3] => 3

shall be changed into

[0] => 1
[1] => 2
[2] => 3

Contents 1 PHP 1.1 array_unique 1.2 array_keys, array_flip 2 JavaScript 2.1 two quick functions that seem to do the trick

PHP

array_unique

see php.net. This function preserves the keys, the above would be changed into

[0] => 1
[1] => 2
[3] => 3

which is disastrous if you use for and not foreach

array_keys, array_flip

the following does not preserve the keys

array_keys( array_flip( someArray ));

so the result would indeed be

[0] => 1
[1] => 2
[2] => 3

JavaScript

No solution yet.

There is a native jQuery function that does exactly this, but it only works if the array elements are DOM elements.

two quick functions that seem to do the trick

Maybe these functions provide what you need (further testing needed).

function arrayUnique(arr) {
  var unq_arr = [];
  for(var i=0, len = arr.length; i<len; i++) {
    if (typeof arr[i] !== 'undefined' && indexOf(arr[i], unq_arr) === -1) {
      unq_arr.push(arr[i]);
    }
  }
  return unq_arr;
}

function indexOf(needle, haystack) {
  for(var i=0,len=haystack.length; i<len; i++) {
    if (typeof haystack[i] !== 'undefined' && haystack[i] == needle) {
      return i;
    }
  }
  return -1;
}

var arr = [1,2,1,3];
console.dir( arr )
console.dir( arrayUnique(arr) );