PHP：打印关联数组

PHP: Printing Associative Array

提问by Tu Hoang

In PHP, I have an associative array like this

在 PHP 中，我有一个像这样的关联数组

$a = array('who' => 'one', 'are' => 'two', 'you' => 'three');

How to write a foreachloop that goes through the array and access the array key and value so that I can manipulate them (in other words, I would be able to get whoand oneassigned to two variables $keyand $value?

如何编写一个foreach遍历数组并访问数组键和值的循环，以便我可以操作它们（换句话说，我将能够获取who并one分配给两个变量$key和$value?

回答by Thiago Silveira

foreach ($array as $key => $value) {
    echo "Key: $key; Value: $value\n";
}

回答by KingCrunch

@Thiago already mentions the way to access the key and the corresponding value. This is of course the correct and preferred solution.

@Thiago 已经提到了访问键和相应值的方法。这当然是正确和首选的解决方案。

However, because you say

然而，因为你说

so I can manipulate them

所以我可以操纵它们

I want to suggest two other approaches

我想建议另外两种方法

1. If you only want to manipulate the value, access it as reference

   foreach ($array as $key => &$value) {
     $value = 'some new value';
   }
   

2. If you want to manipulate both the key and the value, you should going an other way

   foreach (array_keys($array) as $key) {
     $value = $array[$key];
     unset($array[$key]); // remove old key
     $array['new key'] = $value; // set value into new key
   }
   

1. 如果您只想操作该值，请将其作为参考访问

   foreach ($array as $key => &$value) {
     $value = 'some new value';
   }
   

2. 如果你想同时操作键和值，你应该换一种方式

   foreach (array_keys($array) as $key) {
     $value = $array[$key];
     unset($array[$key]); // remove old key
     $array['new key'] = $value; // set value into new key
   }