我正在寻找一个函数，它可以让我在数组(干草堆)中搜索字符串和数组(如针)，所以我通过@jwueller添加到答案中。

这是我的代码:

/**
 * Recursive in_array function
 * Searches recursively for needle in an array (haystack).
 * Works with both strings and arrays as needle.
 * Both needle's and haystack's keys are ignored, only values are compared.
 * Note: if needle is an array, all values in needle have to be found for it to
 * return true. If one value is not found, false is returned.
 * @param  mixed   $needle   The array or string to be found
 * @param  array   $haystack The array to be searched in
 * @param  boolean $strict   Use strict value & type validation (===) or just value
 * @return boolean           True if in array, false if not.
 */
function in_array_r($needle, $haystack, $strict = false) {
     // array wrapper
    if (is_array($needle)) {
        foreach ($needle as $value) {
            if (in_array_r($value, $haystack, $strict) == false) {
                // an array value was not found, stop search, return false
                return false;
            }
        }
        // if the code reaches this point, all values in array have been found
        return true;
    }

    // string handling
    foreach ($haystack as $item) {
        if (($strict ? $item === $needle : $item == $needle)
            || (is_array($item) && in_array_r($needle, $item, $strict))) {
            return true;
        }
    }
    return false;
}

更短的版本，用于基于数据库结果集创建的多维数组。

function in_array_r($array, $field, $find){
    foreach($array as $item){
        if($item[$field] == $find) return true;
    }
    return false;
}

$is_found = in_array_r($os_list, 'os_version', 'XP');

如果$os_list数组在os_version字段中包含'XP'则返回。

$userdb = Array
(
    (0) => Array
        (
            ('uid') => '100',
            ('name') => 'Sandra Shush',
            ('url') => 'urlof100'
        ),

    (1) => Array
        (
            ('uid') => '5465',
            ('name') => 'Stefanie Mcmohn',
            ('url') => 'urlof5465'
        ),

    (2) => Array
        (
            ('uid') => '40489',
            ('name') => 'Michael',
            ('url') => 'urlof40489'
        )
);

$url_in_array = in_array('urlof5465', array_column($userdb, 'url'));

if($url_in_array) {
    echo 'value is in multidim array';
}
else {
    echo 'value is not in multidim array';
}

我发现下面的解决方案不是很干净的代码，但它的工作。它被用作递归函数。

function in_array_multi( $needle, $array, $strict = false ) {
  foreach( $array as $value ) { // Loop thorugh all values
    // Check if value is aswell an array
    if( is_array( $value )) {
      // Recursive use of this function
      if(in_array_multi( $needle, $value )) {
        return true; // Break loop and return true
      }
    } else {
      // Check if value is equal to needle
      if( $strict === true ) {
        if(strtolower($value) === strtolower($needle)) {
          return true; // Break loop and return true
        }
      }else {
        if(strtolower($value) == strtolower($needle)) {
          return true; // Break loop and return true
        }
      }
    }
  }

  return false; // Nothing found, false
}

我使用的这种方法适用于任意数量的嵌套，不需要黑客

<?php
    $blogCategories = [
        'programing' => [
            'golang',
            'php',
            'ruby',
            'functional' => [
                'Erlang',
                'Haskell'
            ]
        ],
        'bd' => [
            'mysql',
            'sqlite'
        ]
    ];
    $it = new RecursiveArrayIterator($blogCategories);
    foreach (new RecursiveIteratorIterator($it) as $t) {
        $found = $t == 'Haskell';
        if ($found) {
           break;
        }
    }

这个也可以。

function in_array_r($item , $array){
    return preg_match('/"'.preg_quote($item, '/').'"/i' , json_encode($array));
}

用法:

if(in_array_r($item , $array)){
    // found!
}