PHP remove commas from numeric strings

Question

In PHP, I have an array of variables that are ALL strings. Some of the values stored are numeric strings with commas.

What I need:

A way to trim the comma

Answer 1

Do it the other way around:

$a = "1,435";
$b = str_replace( ',', '', $a );

if( is_numeric( $b ) ) {
    $a = $b;
}