PHP trim

Summary: in this tutorial, you’ll learn how to use the PHP trim() function to remove whitespace or other characters from both ends of a string.

Introduction to the PHP trim() function

The trim() function removes the whitespaces or other characters from the beginning and end of a string.

Here’s the syntax of the trim() function:

trim ( string $string , string $characters = " \n\r\t\v\0" ) : string
Code language: PHP (php)

The trim() function has two parameters:

  • $string is the input string that will be trimmed.
  • $characters argument is optional. It specifies which character to remove from both ends of the $string.

By default, the trim() function removes the following characters:

CharacterASCIIHexDescription
” “320x20a space
“\t”90x09a tab
“\n”100x0Aa new line
“\r”130x0Da return
“\0”00x00a NUL-byte
“\v”110x0Ba vertical tab

If you want to remove other characters, you can specify them in the $characters argument.

To specify a range of characters to remove, you can use the ‘..’. For example, to remove all ASCII control characters from both ends of a string, you use the following value for the $characters argument:

'\x00..\x1F'
Code language: PHP (php)

It’s important to note that the trim() function doesn’t change the input string. It returns a new string with all the $characters removed.

PHP trim() function examples

Let’s take some examples of using the PHP trim() function.

1) Using the PHP trim() function to remove whitespace from both ends of a string

The following example uses the trim() function to remove spaces from the beginning and the end of a string:

<?php $str = ' PHP '; $new_str = trim($str); var_dump($new_str);
Code language: PHP (php)

Output:

string(3) "PHP"
Code language: plaintext (plaintext)

2) Using the PHP trim() function to remove other characters

Suppose you have the following URL:

https://www.phptutorial.net/api/v1/posts/
Code language: PHP (php)

To get the request URI, you access the $_SERVER array with the key 'REQUEST_URI':

<?php $uri = $_SERVER['REQUEST_URI']; echo $uri;
Code language: PHP (php)

Output:

/api/v1/posts/
Code language: plaintext (plaintext)

The URI contains both leading and trailing slashes.

To remove the slashes (/) from both ends of the URI, you can use the trim() function:

<?php $uri = $_SERVER['REQUEST_URI']; echo trim($uri,'/');
Code language: PHP (php)

Output:

api/v1/posts
Code language: plaintext (plaintext)

Summary

  • Use the PHP trim() function to remove whitespaces or other characters from both ends of a string.
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