trim - PHP ltrim behavior with character list

Question

I was trying to achieve stripping off some beginning part from a string using php ltrim function. It works fine until it get a i character after colon : . if it find i after colon it simply ignore the i character. I know it can be done with substr or any other way but I want to know why its happening with trim. For example.

ltrim('mailto:bob@example.com','mailto:');

the above function will return bob@example.com

but if I put i after colon.. for example

ltrim('mailto:info@example.com','mailto:');

this one will return nfo@example.com

Can anybody explain what is happening?

Answer 1

The second argument to ltrim is a list of characters to remove from the left side of the string.

If you did

<?php
    ltrim('lllliiiiaaaaaatttttt', 'mailto:');
?>

You would get an empty string as the return value.

Try this instead:

<?php
    $email = 'mailto:bob@example.com';
    $fixedEmail = substr($email, 0, 7) == 'mailto:' ? substr($email, 7) : $email;
?>