CODEWITHSUNDEEP
phpregex
fishcracker
fishcracker

Reputation: 2499

`preg_match` the Whole String in PHP

This thing really confuses me, pardon my ignorance.

I have a var $name in here that I want to be free from number, I don't want any digit to be included in it. My preg_match() is this:

var_dump(preg_match('/[^\d]/',$name));

Test cases:

$name = "213131"; // int(0) 
$name = "asdda"; // int(1)
$name = "as232dda"; // int(1)

What I want is to have the third case to be int(0) too.

I'm really a hard time understanding this preg_match(), docs say it return 1 if a pattern match a subject. Here in my case, I use a negated class.

Upvotes: 0

Views: 430

Answers (3)

Chris
Chris

Reputation: 5605

Try this:

<?php
    $string = "as232dda";
    $new_string = trim(str_replace(range(0,9),'',$string));
    echo $new_string;// gives 'asdda'
?>

Or function form:

<?php
  function remove_numbers($string){
    return(trim(str_replace(range(0,9),'',$string)));
  }

  $string = "as232dda";
  echo remove_numbers($string); // gives 'asdda'
?>

Upvotes: 0

dan1111
dan1111

Reputation: 6566

Your regex only checks that there is at least one non-digit. Instead, you need to check that it is only non-digits:

var_dump(preg_match('/^\D+$/',$name));

(^ and $ are the beginning and end of the string. \D means anything not a digit--the opposite of \d. So this only matches non-digits from beginning to end. It doesn't match an empty string. Replace + with * if you want to match an empty string as well).

Upvotes: 1

Explosion Pills
Explosion Pills

Reputation: 191729

#3 matches because you have both letters and numbers. Your regex in English basically says

it matches if there is a non-digit character

If you want to match only non-digit characters, you have to have the regex match against the entire string and allow for an arbitrary number of characters:

^[^\d]+$

Upvotes: 4

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