array_walk相当于foreach:

$arr = ['Client'=>'jQuery','Server'=>'PHP']; array_walk($arr, function($v, $k) { echo "键:$k 值:$v\n"; });

比如去除数组$arr元素的前后空白:

array_walk($arr, function(&$v) { $v = trim($v); });foreach($arr as &$v) { $v = trim($v); } array_filter: 用回调函数过滤数组中的单元,返回过滤后的数组 var_export( array_filter([1, 2, 3], function($v) { return $v > 1; }) ); 和foreach([1, 2, 3] as $k => $v) { if($v > 1) { $tmp[$k] = $v; } } var_export($tmp); 都输出:array ( 1 => 2, 2 => 3, )

PHP数组映射化简(MapReduce):

array_map/array_reduce array_map: 将回调函数作用到给定数组的单元上 var_export( array_map(function ($v) { return $v * $v; }, [1, 2, 3]) ); 和 foreach([1, 2, 3] as $v) { $tmp[] = $v * $v; } var_export($tmp); 都输出: array ( 0 => 1, 1 => 4, 2 => 9, )

array_reduce: 用回调函数迭代地将数组简化(reduce)为单一的值//输出16,即10+1+2+3,其中10作为初始值.

echo array_reduce([1, 2, 3], function($result, $item) { $result = $result + $item; return $result; }, 10); 用foreach表达: $result = 10; foreach([1, 2, 3] as $v) { $result = $result + $v; } echo $result;

执行效果都一样，但是具体的用函数快还是用foreach快些啊