获取上一个数组键的值[重复]

Question

This question already has an answer here:

• PHP get previous array element knowing current array key 9 answers

So I tried doing this :

$array = array('first'=>'111', 'second'=>'222', 'third'=>'333');

var_dump(prev($array["second"]));

Hoping to get 111 but I get NULL. Why?

$array["second"] returns 222. Shouldn't we get 111 when we use PHP's prev() function?

How to get the previous value of an array if it exists using the key?

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Answer 1

Your current value from $array["second"] is not an array and prev takes an array as a parameter.

You have to move the internal pointer of the $array and then get the previous value.

$array = array('first'=>'111', 'second'=>'222', 'third'=>'333');
while (key($array) !== "second") next($array);
var_dump(prev($array));