PHP相当于Python的enumerate()？

Question

在Python中我可以写:

for i, val in enumerate(lst):
    print i, val

我知道如何在PHP中执行此操作的唯一方法是:

for($i = 0; $i < count(lst); $i++){
    echo "$i $val\n";
}

PHP中有更清洁的方法吗？

Answer 1

不要相信PHP数组,它们就像Python dicts.如果您想要安全代码,请考虑以

<?php
$lst = array('a', 'b', 'c');

// Removed a value to prove that keys are preserved
unset($lst[1]);

// So this wont work
foreach ($lst as $i => $val) {
        echo "$i $val \n";
}

echo "\n";

// Use array_values to reset the keys instead
foreach (array_values($lst) as $i => $val) {
        echo "$i $val \n";
}
?>

-

0 a 
2 c 

0 a 
1 c 

Answer 2

用途foreach:

foreach ($lst as $i => $val) {
    echo $i, $val;
}