How do you replace all numbers in a string with a defined character in PHP?

Question

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How would you replace all numbers in a string with a pre-defined character?

Replace each individual number with a dash "-".

$str = "John is 28 years old and donated $40.39!";

Desired output:

"John is -- years old and donated $--.--!"

I am assuming preg_replace() will be used but I am not sure how to target just numbers.

Answer 1

Simple solution using strtr(to translate all digits) and str_repeat functions:

$str = "John is 28 years old and donated $40.39!";
$result = strtr($str, '0123456789', str_repeat('-', 10));

print_r($result);

The output:

John is -- years old and donated $--.--!

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As alternative approach you may also use array_fill function(to create "replace_pairs"):

$str = "John is 28 years old and donated $40.39!";
$result = strtr($str, '0123456789', array_fill(0, 10, '-'));

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http://php.net/manual/en/function.strtr.php

Answer 2

PHP code demo

<?php

$str = "John is 28 years old and donated $40.39!";
echo preg_replace("/\d/", "-", $str);

OR:

<?php

$str = "John is 28 years old and donated $40.39!";
echo preg_replace("/[0-9]/", "-", $str);

Output: John is -- years old and donated $--.--!