javascript 如何打印数组索引
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How to print array index
提问by user762267
Hi Guys Actually I want to print the array index for some purpose.Can anybody tell me about this ?
嗨，伙计们，实际上我想出于某种目的打印数组索引。有人可以告诉我吗？
回答by Oliver A.
Get the first index of an elemnt:
获取元素的第一个索引：
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
$key = array_search('green', $array); // $key = 2;
echo $key;
For all elemnts
对于所有元素
foreach($array as $key => $value){
echo "{$key} => {$value}\n";
}
will output
会输出
0 => blue
1 => red
2 => green
3 => red
All keys:
所有键：
echo implode(', ',array_keys($array));
will output
会输出
0, 1, 2, 3
回答by Touchpad
not sure what you mean with this question but you could try
不确定你对这个问题的意思，但你可以试试
echo "<pre>";
print_r ($arr);
echo "</pre>";
that way you'll see your entire array including all the indexes
这样你就会看到你的整个数组，包括所有的索引
回答by Chris Laarman
if you mean the keys of the array:
如果你的意思是数组的键：
$array = array(0 => 100, "color" => "red");
print_r(array_keys($array));
//result
Array
(
[0] => 0
[1] => color
)
This will provide an array of the keys
这将提供一组键
