Question

我刚刚调查了我的七个朋友关于他们最喜欢的水果（不是！），我想以数组形式提供结果。

Array ( [Apple] => 4 [Orange] => 1 [Strawberry] => 2 [Pear] => 0 ).

我想出了一个解决方案，但看起来很优雅。有没有办法在'foreach'中执行此操作，而不必使用数组合并。谢谢。

// Set the array of favourite fruit options.

$fruitlist = array('Apple', 'Orange', 'Strawberry', 'Pear');

// Survey results from seven people
$favouritefruitlist = array('Apple', 'Apple', 'Orange', 'Apple','Strawberry', 'Apple', 'Strawberry');

// Create an array to count the number of favourites for each option
$fruitcount = [];
   foreach ($fruitlist as $favouritefruit) {
      $fruitcount[] = count(array_keys($favouritefruitlist, $favouritefruit));
    }

// Combine the keys and the values
$fruitcount = array_combine ($fruitlist, $fruitcount);

print_r($fruitcount);

Answer 1

试试array_count_values

$fruitcount = array_count_values($favouritefruitlist);

要同时为0值，请尝试：

$initial = array_fill_keys($fruitlist, 0);
$counts = array_count_values($favouritefruitlist);
$fruitcount = array_merge($initial, $counts);

Answer 2

如果您仍想使用foreach而非array_count_values，则应首先循环$fruitlist以构建密钥，然后通过$favouritefruitlist填充数组，就这样：

<?php
// Set the array of favourite fruit options.
$fruitlist = array('Apple', 'Orange', 'Strawberry', 'Pear');

// Survey results from seven people
$favouritefruitlist = array('Apple', 'Apple', 'Orange', 'Apple', 'Strawberry', 'Apple', 'Strawberry');

// Create an array to count the number of favourites for each option
$fruitcount = [];
foreach ($fruitlist as $fruit) {
    $fruitcount[$fruit] = 0;
}
foreach ($favouritefruitlist as $favouritefruit) {
    $fruitcount[$favouritefruit]++;
}

print_r($fruitcount);

结果：

Array
(
    [Apple] => 4
    [Orange] => 1
    [Strawberry] => 2
    [Pear] => 0
)

（顺便说一句，我不能相信你的朋友都不喜欢梨......）

使用另一个数组中的值计数创建一个数组，其值为键，计数为值

2 个答案: