PHP regular expression - filter number only

Question

I know this might sound as really dummy question, but I\'m trying to ensure that the provided string is of a number / decimal format to use it later on with PHP\'s number_fo

Answer 1

To remove anything that is not a number:

$output = preg_replace('/[^0-9]/', '', $input);

Explanation:

• [0-9] matches any number between 0 and 9 inclusively.
• ^ negates a [] pattern.
• So, [^0-9] matches anything that is not a number, and since we're using preg_replace, they will be replaced by nothing '' (second argument of preg_replace).

Answer 2

Using is_numeric or intval is likely the best way to validate a number here, but to answer your question you could try using preg_replace instead. This example removes all non-numeric characters:

$output = preg_replace( '/[^0-9]/', '', $string );

Answer 3

use built in php function is_numeric to check if the value is numeric.

Answer 4

You can try that one:

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

Cheers.

Answer 5

Another way to get only the numbers in a regex string is as shown below:

$output = preg_replace("/\D+/", "", $input);

Answer 6

You could do something like this if you want only whole numbers.

function make_whole($v){
    $v = floor($v);
    if(is_numeric($v)){
      echo (int)$v;
      // if you want only positive whole numbers
      //echo (int)$v = abs($v);
    }
}