Recursive In Array

Recursive In Array

Here is a function that which functions in the same manner as the PHP in_array() function, except this will search recursively through a multidimensional array. The recursive in_array function takes two parameters and an optional third.

Just like in_array() the function searches $array for any occurrence of $string. If the optional third parameter is set to true, the function will check for type also. Recursively search a multi-dimensional array easily with this.


<?php

    /**
    *
    * @recursively check if a value is in array
    *
    * @param string $string (needle)
    *
    * @param array $array (haystack)
    *
    * @param bool $type (optional)
    *
    * @return bool
    *
    */
    function in_array_recursive($string, $array, $type=false)
    {
        /*** an recursive iterator object ***/
        $it = new RecursiveIteratorIterator(new RecursiveArrayIterator($array));

        /*** traverse the $iterator object ***/
        while($it->valid())
        {
            /*** check for a match ***/
            if( $type === false )
            {
                if( $it->current() == $string )
                {
                    return true;
                }
            }
            else
            {
                if( $it->current() === $string )
                {
                    return true;
                }
            }
            $it->next();
        }
        /*** if no match is found ***/
        return false;
    }


    /*** example usage ***/

    /*** the array to search ***/
    $array = array(
            array('cat', 'dog', 'mouse'),
            array('dingo', 'wombat', 'emu'),
            array('fish', array('whale', 'shark'), 'stingray'),
            'steve irwin'
            );
            

    /*** the string to search for ***/
    $string = 'whale';

    /*** check if the string is in the array ***/
    if( in_array_recursive( $string, $array ) )
    {
        echo 'found ' . $string;
    }
    else
    {
        echo $string . ' not found.';
    }?>