<?php //array_filter(arg1,arg2) arg1:必填数组,arg2可不填 //实例1:去除数组中的空元素,保留数组之前键值 $arr3 = [0,false,null,1,2,3,4,5,""," "]; $kong = array_filter($arr3); var_dump($kong); echo "<hr/>"; //实例2:用回调函数过滤数组中的元素 function test_odd($var) { return($var & 1);//位与运算 3转换为二进制 0011 与 0001 位与运算结果为0001 4转为二进制是 0100 } $a1=array("a","b",2,3,4); print_r(array_filter($a1,"test_odd")); echo "<hr/>"; //array_diff 比较两个数组的键值,并返回差集 $arr1 = [1,2,3]; $arr2 = [1]; $diff = array_diff($arr1,$arr2); print_r($diff); echo "<hr/>"; //获取二维数组中的某一键值,组成新的数组 php版本大于 5.5 $arr4 = array( 0 => ['id'=>1,'name'=>'zhangsan1'], 1 => ['id'=>2,'name'=>'zhangsan2'], 2 => ['id'=>3,'name'=>'zhangsan3'], 3 => ['id'=>4,'name'=>'zhangsan4'] ); $new_arr = array_column($arr4,"name"); print_r($new_arr); ?>
运行结果: