这篇文章给大家分享六个比较好用的php数组Array函数，非常不错，具有一定的参考借鉴价值，需要的朋友参考下吧
1. array_column 返回输入数组中某个单一列的值。
2. array_filter 用回调函数过滤数组中的元素。
3. array_map 将用户自定义函数作用到给定数组的每个值上，返回新的值。
4. array_walk_recursive 对数组中的每个成员递归地应用用户函数。
5. extract (从数组中将变量导入到当前的符号表), compact (创建一个包含变量名和它们的值的数组)
6. uasort 使用用户自定义的比较函数对数组中的键值进行排序。
1. array_column 返回输入数组中某个单一列的值。
类似功能有
1.1 Yii2 中的 ArrayHelper::index($array, 'id');
1.2 Yii2 中的 $query->select(['last_name', 'id'])->indexBy('id')->column();
// 可能从数据库中返回数组 $a = array( array( 'id' => 5698, 'first_name' => 'Peter', 'last_name' => 'Griffin', ), array( 'id' => 4767, 'first_name' => 'Ben', 'last_name' => 'Smith', ), array( 'id' => 3809, 'first_name' => 'Joe', 'last_name' => 'Doe', ) ); $last_names = array_column($a, 'last_name', 'id'); print_r($last_names);
输出结果:
Array
(
[5698] => Griffin
[4767] => Smith
[3809] => Doe
)2. array_filter 用回调函数过滤数组中的元素。
function test_odd($var)
{
return($var & 1);
}
$a1=array("a","b",2,3,4);
print_r(array_filter($a1,"test_odd"));输出:
Array
(
[2] => 2
[3] => 3
[4] => 4
)3. array_map 将用户自定义函数作用到给定数组的每个值上，返回新的值。
此函数有点类似与 array_walk_recursive , 只是多写了一步递归
function myfunction($v) {
if (is_array($v)) {
return array_map("myfunction", $v);
}
return($v * $v);
}
$a = array(1, 2, 3, 4, 5, 6 => [2, 3]);
print_r(array_map("myfunction", $a));输出:
Array( [0] => 1 [1] => 4 [2] => 9 [3] => 16 [4] => 25 [6] => Array([0] => 4 [1] => 9) )
function myfunction($v1, $v2) {
if ($v1 === $v2) {
return "same";
}
return "different";
}
$a1 = array("Horse", "Dog", "Cat");
$a2 = array("Cow", "Dog", "Rat");
print_r(array_map("myfunction", $a1, $a2));输出:
Array( [0] => different [1] => same [2] => different )
4. array_walk_recursive 对数组中的每个成员递归地应用用户函数。
此函数有点类似与 array_map, 只是省去了写递归
function myfunction(&$value, $key, $p) {
if ($value == 'xxx') {
$value = $p;
}
}
$a = array("a" => "red", "b" => "green", "c" => "blue", 'd' => ['x' => 'xxx', 'y' => 'yyy']);
array_walk_recursive($a, "myfunction", 'green');
print_r($a);输出:
Array( [a] => red [b] => green [c] => blue [d] => Array([x] => green [y] => yyy) )
5. extract (从数组中将变量导入到当前的符号表), compact (创建一个包含变量名和它们的值的数组)
$a = "Original";
$my_array = array("a" => "Cat","b" => "Dog", "c" => "Horse");
extract($my_array);
echo "\$a = $a; \$b = $b; \$c = $c";输出:
$a = Cat; $b = Dog; $c = Horse
$firstname = "Peter";
$lastname = "Griffin";
$age = "41";
$result = compact("firstname", "lastname", "age");
print_r($result);输出:
Array
(
[firstname] => Peter
[lastname] => Griffin
[age] => 41
)6. uasort 使用用户自定义的比较函数对数组中的键值进行排序(可以对二维数组排序)。
$arr2 = [
[
'id' => 3,
'age' => 33,
],
[
'id' => 2,
'age' => 44,
],
[
'id' => 1,
'age' => 22,
],
];
//按age字段升序排序
uasort($arr2, function($a, $b) {
$field = 'age';
if ($a[$field] == $b[$field]){
return 0;
}
return ($a[$field] < $b[$field]) ? -1 : 1;
});
print_r($arr2);输出:
Array(
[2] => Array([id] => 1 [age] => 22 )
[0] => Array([id] => 3 [age] => 33 )
[1] => Array([id] => 2 [age] => 44 )
)The above is the detailed content of Share six easy-to-use PHP array Array functions_php examples. For more information, please follow other related articles on the PHP Chinese website!
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
