使用str_pad（PHP）递增数字[关闭]

Question

I am creating an incrementing number starting with 1001. If the number goes 1001,1002,1003... when it reaches 10, will it be formatted like 1010 or will it be 10010? I need it to just go in order and be 1010 and when it reaches 100, 1100.

$prefix = "1"; // update the prefix here

    $number = 1;
    $number++;
    $unique = str_pad($number, 3, "0", STR_PAD_LEFT);
    $unique = $prefix . $unique;

print_r($unique);

Answer 1

When your count reaches 10, the number printed will be 1010. As described here, str_pad "Pads a string to a certain length with another string" You can create a test with the following:

$prefix = "1"; // update the prefix here

$number = 1;

for ($number = 1; $number <= 100; $number++)
{    
  $unique = str_pad($number, 3, "0", STR_PAD_LEFT);
  $unique = $prefix . $unique;    
  print($unique."
");
 }

When your count reaches 100, the number printed will be 1100.

However, if you were to go up to 1000, 11000 would be printed - str_pad apparently will not truncate the string to match the specified size.