Remove non-numeric characters (excluding periods and commas) from a string (i.e. remove all characters except numbers, commas, and periods)
PhpPhp Problem Overview
If I have the following values:
$var1 = AR3,373.31
$var2 = 12.322,11T
How can I create a new variable and set it to a copy of the data that has any non-numeric characters removed, with the exception of commas and periods? The values above would return the following results:
$var1_copy = 3,373.31
$var2_copy = 12.322,11
Php Solutions
Solution 1 - Php
You could use preg_replace to swap out all non-numeric characters and the comma and period/full stop as follows:
$testString = '12.322,11T';
echo preg_replace('/[^0-9,.]+/', '', $testString);
The pattern can also be expressed as /[^\d,.]+/
Solution 2 - Php
I'm surprised there's been no mention of filter_var here for this being such an old question...
PHP has a built in method of doing this using sanitization filters. Specifically, the one to use in this situation is FILTER_SANITIZE_NUMBER_FLOAT with the FILTER_FLAG_ALLOW_FRACTION | FILTER_FLAG_ALLOW_THOUSAND flags. Like so:
$numeric_filtered = filter_var("AR3,373.31", FILTER_SANITIZE_NUMBER_FLOAT,
FILTER_FLAG_ALLOW_FRACTION | FILTER_FLAG_ALLOW_THOUSAND);
echo $numeric_filtered; // Will print "3,373.31"
It might also be worthwhile to note that because it's built-in to PHP, it's slightly faster than using regex with PHP's current libraries (albeit literally in nanoseconds).
Solution 3 - Php
Simplest way to truly remove all non-numeric characters:
echo preg_replace('/\D/', '', $string);
\D represents "any character that is not a decimal digit"
Solution 4 - Php
You could use filter_var to remove all illegal characters except digits, dot and the comma.
- The
FILTER_SANITIZE_NUMBER_FLOATfilter is used to remove all non-numeric character from the string. FILTER_FLAG_ALLOW_FRACTIONis allowing fraction separator" . "- The purpose of
FILTER_FLAG_ALLOW_THOUSANDto get comma from the string.
Code
$var1 = '12.322,11T';
echo filter_var($var1, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION | FILTER_FLAG_ALLOW_THOUSAND);
Output
12.322,11
To read more about filter_var() and Sanitize filters
Solution 5 - Php
If letters are always in the beginning or at the end, you can simply just use trim...no regex needed
$string = trim($string, "a..zA..Z"); // this also take care of lowercase
"AR3,373.31" --> "3,373.31"
"12.322,11T" --> "12.322,11"
"12.322,11" --> "12.322,11"