PHP:从数组获取密钥？

Question

我确信这是PHP中的超级简单和内置函数,但我还没有看到它.

这就是我现在正在做的事情:

foreach($array as $key => $value) {
    echo $key; // Would output "subkey" in the example array
    print_r($value);
}

我可以做类似下面的事情,从而避免在每个foreach循环中写"$ key => $ value"吗？(伪码)

foreach($array as $subarray) {
    echo arrayKey($subarray); // Will output the same as "echo $key" in the former example ("subkey"
    print_r($value);
}

谢谢!

数组:

Array
(
    [subKey] => Array
        (
            [value] => myvalue
        )

)

Answer 1

You can use key():

<?php
$array = array(
    "one" => 1,
    "two" => 2,
    "three" => 3,
    "four" => 4
);

while($element = current($array)) {
    echo key($array)."\n";
    next($array);
}
?>

Answer 2

使用该array_search功能.

来自php.net的示例

$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array);   // $key = 1;

Answer 3

$foo = array('a' => 'apple', 'b' => 'ball', 'c' => 'coke');

foreach($foo as $key => $item) {
  echo $item.' is begin with ('.$key.')';
}

Answer 4

$array = array(0 => 100, "color" => "red");
print_r(array_keys($array));

Answer 5

如果它是foreach您在问题中描述的循环,则使用$key => $value快速且高效.