foreach中的$ k => $ v($ ex为$ k => $ v)是什么意思？

Question

可能重复:
PHP中"=>"是什么意思？

什么$k => $v意思？

Answer 1

这意味着对于可遍历变量中的每个键值对$ex,键都被赋值给$k并赋值$v.换一种说法:

$ex = array("1" => "one","2" => "two", "3" => "three");
foreach($ex as $k=>$v) {
   echo "$k : $v \n";
}

输出:

1 : one
2 : two
3 : three

Answer 2

$k是将$v值存储在数组中的索引号。$k可以是数组的关联索引：

$array['name'] = 'shakti';
$array['age'] = '24';

foreach ($array as $k=>$v)
{
    $k points to the 'name' on first iteration and in the second iteration it points to age.
    $v points to 'shakti' on first iteration and in the second iteration it will be 24.
}