在PHP中动态填充关联数组

Question

我有一个包含以下6个字符串的数组.

user1 A
user2 B
user4 C
user2 D
user1 E

我需要创建一个像这样的字典:

arr['user1'] => ['A', 'E']
arr['user2'] => ['B', 'D']
arr['user4'] => ['C']

如何在PHP中执行此操作？

Answer 1

这看似有效......

$arr = array();

foreach($lines as $line) {
    list($user, $letter) = explode(" ", $line);
    $arr[$user][] = $letter;
}

CodePad.