Question

是否可以“提取”数组的前3个元素，然后将这3个元素混洗并将其添加回数组中？

这是一个滑块，前三个幻灯片应该在每个页面加载中随机显示...

有人可以帮忙吗？

 public function shuffle( $data ) {

    // Return early there are no items to shuffle.
    if ( ! is_array( $data['slider'] ) ) {
        return $data;
    }

    // Prepare variables.
    $random = array();
    $keys   = array_keys( $data['slider'] );

    // Shuffle the keys and loop through them to create a new, randomized array of images.
    shuffle( $keys );
    foreach ( $keys as $key ) {
        $random[$key] = $data['slider'][$key];
    }

    // Return the randomized image array.
    $data['slider'] = $random;
    return $data;

}

/ * -----------------------更新--------------------- -* /

这是对我有用的方法，但是为什么呢？我对php相对陌生； D

public function shuffle($data) {

    // Return early there are no items to shuffle.
    if (!is_array($data['slider'])) {
        return $data;
    }

    $sliced_array = array_slice($data["slider"], 0, 3, TRUE);
    // Shuffle the keys and loop through them to create a new, randomized array of images.
    shuffle($sliced_array);


    $data['slider'] = $sliced_array + array_slice($data["slider"], 0);

    return $data;
}

Answer 1

<?php 
$data = [1,2,3,4,5,6,7,8,9];

//get 3 first elements and remove 3 first elements from main array
$remains = array_splice($data,3);

//shuffle 3 elements
shuffle($data);

//join everything back
$data = array_merge(array_values($data), array_values($remains));

Answer 2

是的，有可能。你走在正确的轨道上。经过一些调整，效果很好。

代码：

public function shuffling($data) {

    // Return early there are no items to shuffle.
    if (!is_array($data['slider'])) {
        return $data;
    }

    $sliced_array = array_slice($data["slider"], 0, 3, TRUE);
    // Shuffle the keys and loop through them to create a new, randomized array of images.
    shuffle($sliced_array);

    foreach ($sliced_array as $key => $value) {
        $data['slider'][$key] = $value;
    }
    return $data;
}

我已经尝试过使用示例数组：

shuffling(["slider" => [
        0 => "A",
        1 => "B",
        2 => "C",
        3 => "D",
        4 => "E",
]]);

结果是：

Array
(
    [slider] => Array
        (
            [0] => B
            [1] => C
            [2] => A
            [3] => D
            [4] => E
        )

)

注意：shuffle已经在php中定义了功能。这就是为什么我将名称更改为shuffling的原因。

Answer 3

这是一个演示：https://3v4l.org/rYfV2

public function shuffler($data) {

    // Return early there are no items to shuffle.
    if (!is_array($data['slider'])) {
        return $data;
    }

    // Generate a copy of first three elements.
    $first = array_slice($data['slider'], 0, 3);

    // Shuffle first three elements.
    shuffle($first);

    // Overwrite original first three elements.
    $data['slider'] = array_replace($data['slider'], $first);
    // $data['slider'] = $first + $data['slider'];  // function-less alternative

    // Return the randomized image array.
    return $data;

}

array_replace()避免以更冗长/重复的方式进行替换过程。当您只希望处理前三个元素时，它也避免处理整个数组。完全没有必要致电array_values()。

您也可以使用并运算符代替array_replace() －在array_replace()行下查看我的注释代码行。（Demo）

来自PHP Documentation Array Operator：

+运算符返回添加到左侧的右侧数组数组对于两个数组中都存在的键，将使用左侧数组，并且来自右侧数组将被忽略。

PHP-提取数组的前3个元素->将其随机播放->并将它们添加回原始文件中。阵列

3 个答案: