PHP - 如何使用trim可选的character_mask去除我想要剥离的所有字符

Question

I need some help understanding the trim function. From the docs, its says the following about character_mask:

character_mask Optionally, the stripped characters can also be specified using the character_mask parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

When I test by specifying trim($num,"$\,"), its not working as I expected.

$num = '$1,000.00';

$findSymbol = strpos($num, '$'); // find $ symbol
if ($findSymbol === false) {
    $num = $num;
}else{
    $num = trim($num,"$\,"); // strip the $ and the , symbol
}

var_dump($num); //OUTPUT: 1,000.00

Basically, all I want is strip the $ and the , symbols all together so the output would look like this:

1000.00

Any help is greatly appreciated. Thanks!

Answer 1

trim() strips the listed characters from the beginning and/or end of the string as described in the docs you've quoted.

Strip whitespace (or other characters) from the beginning and end of a string

If you want to remove characters from the middle of a string, use str_replace()

$num = str_replace(['$', ','], '', $num); 

You can also use the two functions in combination:

$num = str_replace(',', '', trim($num, '$'));