PHP计算变量值前加0

Question

如何让PHP计算出现0的例子:

$a = "00001";
$b = "00005";

$total = $a + $b;

预期结果是:00006

Including and keep 0000 出现。

我试过了，但结果总是:6

Answer 1

只需做正常的数学运算，然后在末尾的前面加回零即可:

$a = "00001";
$b = "00005";

$total = $a + $b;
$total = sprintf("%05d", $total );

或

$total = str_pad($total , 5, "0", STR_PAD_LEFT);