Remove non-numeric characters from a string in PHP

This article demonstrates how to remove non-numeric characters from a string in PHP.

1. Using `preg_replace()` function

A simple solution is to use preg_replace() function to remove non-numeric characters from a string. This function needs a regular expression to search and replace within a string.

The following solution uses the [^0-9] regex to match non-numeric characters. Note that this regex also removes +, -, ., ,, e, and E from the string.

<?php

$text = '999-999-9999';

$result = preg_replace('/[^0-9]/', '', $text);

echo $result;

Output: 9999999999

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A better option is to use the \D special character, which matches a non-digit character.

<?php

$text = '999-999-9999';

$result = preg_replace('/\D/', '', $text);

echo $result;

Output: 9999999999

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2. Using `filter_var()` function

Alternatively, you can use the filter_var() function to remove non-numeric characters from the string. The FILTER_SANITIZE_NUMBER_FLOAT sanitization filter removes all characters from the string except digits, +, and -. Note that this also removes the decimal character (.), comma separator (,), and scientific notation (e or E) from the string, unless you specify FILTER_FLAG_ALLOW_FRACTION, FILTER_FLAG_ALLOW_THOUSAND, and FILTER_FLAG_ALLOW_SCIENTIFIC flags, respectively.

<?php

$text = '-99.99$';

$result = filter_var($text, FILTER_SANITIZE_NUMBER_FLOAT,

FILTER_FLAG_ALLOW_FRACTION | FILTER_FLAG_ALLOW_THOUSAND);

echo $result;

Output: -99.99

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That’s all about removing non-numeric characters from a string in PHP.

Remove non-numeric characters from a string in PHP

1. Using preg_replace() function

2. Using filter_var() function

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1. Using `preg_replace()` function

2. Using `filter_var()` function