如何使用PHP有效地在不同位置替换字符串的一部分？

Question

I need to hide parts of a string like this 2345***47563****3432. I used PHP substr_replace as shown below which works but I am thinking if there is a better way of doing it instead of using nested substr_replace like I did.

$mtn = 2348764756783432;
substr_replace(substr_replace($mtn, '***', 3,3 ), '***', 9, 3)
The result is 234***475***3432. 

Answer 1

You can try this:

preg_replace('/(\d{3})(\d){3}/', '$1***', $mtn);

But I am not sure that this one is the easiest to read.
And also, as you mentioned this one have another performance:

$mtn = 2348764756783432;

$time = microtime(true);
$result = substr_replace(substr_replace($mtn, '***', 3,3 ), '***', 9, 3);
printf('Result: %s, Spent time: %f %s', $result, microtime(true) - $time, PHP_EOL);

$time = microtime(true);
$result = preg_replace('/(\d{3})(\d){3}/', '$1***', $mtn);
printf('Result: %s, Spent time: %f %s', $result, microtime(true) - $time, PHP_EOL);

Output:

Result: 234***475***3432, Spent time: 0.000009 
Result: 234***475***3432, Spent time: 0.000092