每天一个常用PHP函数-array_chunk

场景

我们通常从db或者api中获取数组数据，然后进行处理，那如果数据太大怎么办？或者进行api请求的时候数据太大，如何分批进行，array_chunk登场了。

语法

array_chunk ( array $array , int $size [, bool $preserve_keys = FALSE ] ) : array
$array 需要处理的数组
$size 拆分后每个数组的元素数量
$preserve_keys 是否需要保证key不变

分割之后返回多维数组

使用

$userList = [
    ['id' => 1, 'name' => '快乐的鸟', 'totalAmount' => 1000],
    ['id' => 2, 'name' => '愤怒的鸟', 'totalAmount' => 10],
    ['id' => 3, 'name' => '忧伤的鸟', 'totalAmount' => 100],
    ['id' => 4, 'name' => '勤奋的鸟', 'totalAmount' => 3000],
    ['id' => 5, 'name' => '孤单的鸟', 'totalAmount' => 9000],
];

// 两个元素进行分割
print_r(array_chunk($userList, 2));


/**
Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [name] => 快乐的鸟
                    [totalAmount] => 1000
                )

            [1] => Array
                (
                    [id] => 2
                    [name] => 愤怒的鸟
                    [totalAmount] => 10
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [id] => 3
                    [name] => 忧伤的鸟
                    [totalAmount] => 100
                )

            [1] => Array
                (
                    [id] => 4
                    [name] => 勤奋的鸟
                    [totalAmount] => 3000
                )

        )

    [2] => Array
        (
            [0] => Array
                (
                    [id] => 5
                    [name] => 孤单的鸟
                    [totalAmount] => 9000
                )

        )

)



**/

上面默认preserve_keys为false, 如果设置为true, 则新数组中的元素仍保持原数组中的索引index

print_r(array_chunk($userList, 2, true));

/**
Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [name] => 快乐的鸟
                    [totalAmount] => 1000
                )

            [1] => Array
                (
                    [id] => 2
                    [name] => 愤怒的鸟
                    [totalAmount] => 10
                )

        )

    [1] => Array
        (
            [2] => Array
                (
                    [id] => 3
                    [name] => 忧伤的鸟
                    [totalAmount] => 100
                )

            [3] => Array
                (
                    [id] => 4
                    [name] => 勤奋的鸟
                    [totalAmount] => 3000
                )

        )

    [2] => Array
        (
            [4] => Array
                (
                    [id] => 5
                    [name] => 孤单的鸟
                    [totalAmount] => 9000
                )

        )

)




**/