How Can I Effectively Search for a Value in a Multidimensional Array in PHP?

Multidimensional Array Search with in_array()

The in_array() function excels in verifying the existence of a value within a linear array. However, its functionality falls short when it comes to multidimensional arrays. This article delves into the limitations of in_array() in multidimensional scenarios and introduces a recursive solution.

Limitations of in_array() with Multidimensional Arrays

$a = array("Mac", "NT", "Irix", "Linux");<br>if (in_array("Irix", $a)) echo "Got Irix"; // Works<br>

In contrast, applying in_array() to a multidimensional array, as shown below, will yield inaccurate results:

$b = array(array("Mac", "NT"), array("Irix", "Linux"));<br>if (in_array("Irix", $b)) echo "Got Irix"; // Fails<br>

Recursive Solution for Multidimensional Array Search

To effectively search for a value within a multidimensional array, a recursive approach is required. The following code snippet defines a custom function for this purpose:

<br>function in_array_r($needle, $haystack, $strict = false) {</p>
<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">foreach ($haystack as $item) {
    if (($strict ? $item === $needle : $item == $needle) || (is_array($item) &amp;&amp; in_array_r($needle, $item, $strict))) {
        return true;
    }
}

return false;