如何从两个普通数组的值创建关联数组？

Question

代码

<?php
    $a = array('31','01','02','03','30','31','01','02');
    $b = array('7','7','7','7','8','8','8','8');
    $c = array_combine($a,$b);
    var_dump($c);
?>

结果它忽略具有相同键的重复值 array(5) { [31]=> string(1) "8" ["01"]=> string(1) "8" ["02"]=> string(1) "8" ["03"] => 字符串(1) "7" [30]=> 字符串(1) "8" }

我需要什么

我需要创建一个关联数组，键和重复值用逗号分隔。（这里：第 31 个键有两个值 7 和 8）

Answer 1

你的任务可以通过一个简单的方法解决 foreach:

$c = [];
foreach ($a as $key => $value) {
    if (!isset($c[$value])) {
        // there's NO key `$value` in `$c` - add it with initial value
        $c[$value] = [];
    } 

    // add new value to this key
    $c[$value][] = $b[$key];
}
// Output
// Array ( [31] => Array ( [0] => 7 [1] => 8 ) [01] => Array ( [0] => 7 [1] => 8 ) [02] => Array ( [0] => 7 [1] => 8 ) [03] => Array ( [0] => 7 ) [30] => Array ( [0] => 8 )

逗号分隔值的版本：

foreach ($a as $key => $value) {
    if (!isset($c[$value])) {
        // there's NO key `$value` in `$c` - add it with initial value
        $c[$value] = $b[$key];
    } else {
        $c[$value] .= ',' . $b[$key];
    }
}
// Output:
// Array ( [31] => 7,8 [01] => 7,8 [02] => 7,8 [03] => 7 [30] => 8 )

Answer 2

您可以使用"array_push"，例如：

    <?php 
$a = array('31','01','02','03','30','31','01','02'); 
$b = array('7','7','7','7','8','8','8','8'); 
$c = array_push($a, $b); 
var_dump($c);
?>

如何从两个普通数组的值创建关联数组？

How to make an associative array from values of two normal arrays?

php

arrays

associative