src/ArrayLib.php
/**
     * Same as array_diff except that this returns the indexes of the values 
     * that are in array1 but not array2.
     * WARNING - this is NOT comparing the indexes themselves.
     * @param array $array1
     * @param array $array2
     * @return array - array of indexes in array1 where the values are not in 
     *                 array2
     */
Same as array_diff except that this returns the indexes of the values
that are in array1 but not array2.
WARNING - this is NOT comparing the indexes themselves.
@param array $array1
@param array $array2
@return array - array of indexes in array1 where the values are not in
array2
Same as array_diff except that this returns the indexes of the values that are in array1 but not array2 . WARNING - this is NOT comparing the indexes themselves . @param array $array1 @param array $array2 @return array - array of indexes in array1 where the values are not in array2
public static function indexDiff(array $array1, array $array2)
    {
        $indexes = array();
        $flippedArray2 = array_flip($array2); 
        foreach ($array1 as $index => $value)
        {
            if (!isset($flippedArray2[$value])) 
            {
                $indexes[] = $index;
            }
        }
        return $indexes;
    }
public static function indexDiff ( array $ array1 , array $ array2 ) { $ indexes = array ( ) ; $ flippedArray2 = array_flip ( $ array2 ) ; foreach ( $ array1 as $ index => $ value ) { if ( ! isset ( $ flippedArray2 [ $ value ] ) ) { $ indexes [ ] = $ index ; } } return $ indexes ; }
Same as array_diff except that this returns the indexes of the values
 that are in array1 but not array2.
Same as array_diff except that this returns the indexes of the values that are in array1 but not array2 .
# swaps indexes and values