PHP trim() Function

The trim() function in PHP is an inbuilt function which removes whitespaces and also the predefined characters from both sides of a string that is left and right.

Related Functions:

• PHP | ltrim() Function
• PHP | rtrim() Function

Syntax:

trim($string, $charlist)

Parameters:The function accepts one mandatory parameter and one optional parameter as shown in the above syntax and described below.

1. $string: This parameter specifies the string from which the whitespace and predefined characters from left and right are to be removed
2. $charlist: This is an optional parameter which specifies the characters that are to be removed from the string. If this is not mentioned then all of the following characters will be removed:
   • “\0” – NULL
   • “\t” – tab
   • “\n” – new line
   • “\x0B” – vertical tab
   • “\r” – carriage return
   • ” ” – ordinary white space

Return Value: It returns the modified string by removing the whitespace and also the predefined characters from both sides of a string that is left and right.

Below programs illustrate the trim() function:

Program 1:

<?php
// PHP program to demonstrate the use of trim()
// function when second parameter is present

// removes the predefined characters from
// front and back
$str = "Hello World!";
echo trim($str, "Hell!");
?>

Output:

o World

Program 2:

<?php
// PHP program to demonstrate the use of trim()
// function when second parameter is absent

$str = "  geeks for geeks ";

// removes all leading and trailing whitespaces
echo trim($str);
?>

Output:

geeks for geeks

Reference: http://php.net/manual/en/function.trim.php