定义和用法array_map() 函数返回用户自定义函数作用后的数组。
回调函数接受的参数数目应该和传递给 array_map() 函数的数组数目一致。
语法array_map(function,array1,array2,array3...) 参数描述function必需。
用户自定义函数的名称，或者是 null。array1必需。规定数组。array2可选。规定数组。array3可选。规定数组。
例子 1
<span style="font-size: 14px;"><?php</span><br />function myfunction($v) {<br />if ($v === "Dog") {<br />return "Fido";<br />}<br />return $v;<br />}<br /><br />$a = array("Horse", "Dog", "Cat");<br />print_r(array_map("myfunction", $a));<br /><p>?><span style="font-size: 14px;">输出：
Array ( [0] => Horse [1] => Fido [2] => Cat )
例子 2
使用多个参数：
<span style="font-size: 14px;"><?php</span><br />function myfunction($v1, $v2) {<br />if ($v1 === $v2) {<br />return "same";<br />}<br />return "different";<br />}<br /><br />$a1 = array("Horse", "Dog", "Cat");<br />$a2 = array("Cow", "Dog", "Rat");<br />print_r(array_map("myfunction", $a1, $a2));<br /><p>?><span style="font-size: 14px;">输出：
Array ( [0] => different [1] => same [2] => different )
例子 3
请看当自定义函数名设置为 null 时的情况：
<span style="font-size: 14px;"><?php</span><br />$a1 = array("Dog", "Cat");<br />$a2 = array("Puppy", "Kitten");<br />print_r(array_map(null, $a1, $a2));<br /><p>?><span style="font-size: 14px;">输出：
Array (
[0] => Array ( [0] => Dog [1] => Puppy )
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