How to remove the letter of an alphanumeric string

How to remove the letter of an alphanumeric string

In this post, I'll  try to explain how to remove the letter of an alphanumerics string.Maybe this tutorial could be helpful for you :

we have the following code:

  $sMystring = 'Tra789asdf'; //1
  $pMypattern = '/[a-zA-z]/'; //2
  $sMyreplacement = ''; //3
  echo preg_replace($pMypattern, $sMyreplacement, $sMystring);//4
 

Code explanation:

First Line: We have our alphanumeric string ,I mean a combination between numbers and letters.

Second Line: We have out REGEX pattern, which identify the letter in our string $pMypattern.

Third  Line: We have a variable that will use to replace the letter, by that I mean instead of letter we  will have in the string blank spaces.

Fourth Line:  We will have our output and it is important to note the preg_replace
 which  identified in the string the pattern and remove the matches and replace with the new value in our case is: $Myreplacement.


Output : 789

If want the opposite output, I mean remove the number the code will be:

   

    $sMystring = 'Tra789asdf';//1
    $pMypattern = '/[0-9]/';//2
    $sMyreplacement = ''; //3
    echo preg_replace($pMypattern, $sMyreplacement, $sMystring); //4
 

Output :: Traasdf