phpregexpreg-replace

Does preg_replace() modify by reference or return a value?

I'm trying to replace the first 12 digits of credit card numbers with X's in a predictable blob of text that contains the string:

Credit Card Number: 1234123412341234

Here's my PHP function:

preg_replace('/Credit Card Number: ([0-9]{12})/','Credit Card Number: XXXXXXXXXXXX',$str);

The problem is that the input string is not be affected.

Solution

  • Dumb question: you are assigning the returned value back to $str right?

    $str = preg_replace('/(Credit Card Number: [0-9]{12}/','Credit Card Number: XXXXXXXXXXXX',$str);