PHP trim | Remove Characters from Both Sides of String

PHP trim is an inbuilt function in PHP. It removes whitespaces (or other characters) from both the left and right sides of a string. In this article, we will discuss the PHP trim Function. Also, we will discuss a few examples of using it.

To remove characters only from left or right, you can use the following functions:


trim($string, $characterList)


The PHP trim Function expects two parameters. However, only one parameter is mandatory and the other is optional.

  • $string: The first parameter to the function is the string to operate on. It is a mandatory parameter.
  • $characterList: The second parameter to the function is an optional parameter. It specifies the character list to remove from the string. By default, the function removes all the following characters:
    • “\0” – NULL
    • “\t” – tab
    • “\n” – new line
    • “\x0B” – vertical tab
    • “\r” – carriage return
    • ” ” – ordinary white space

Return Value

The trim function in PHP returns the string after removing whitespaces and all other predefined characters from both ends.

Note: The function returns an empty string when the argument is a null variable.

PHP trim Function


Let’s discuss a few examples of using the function.

Example 1: Removing Whitespaces

For instance, consider a simple string containing whitespaces on both ends.


	$string = '   Simple   string ';
	$trimmedString = trim($string);



In the above example, the function removes whitespaces from both ends of the string.

string(15) "Simple   string"

Example 2: Specifying Characters to Remove

Also, we can specify characters to remove by passing the second parameter.

$str = "Hello World!";
echo $str;
//Remove "He" in "Hello" and "d!" in "World"
echo trim($str,"Hed!");

The above example will print the following:

Hello World!
llo Worl

Example 3: Removing Whitespaces from Array of Strings

Similarly, you can remove whitespaces from an array of strings using PHP array_map. We can pass the trim function as callback in array_map function.


$fruit = array('apple','banana ', ' mango ');

$trimmedArray = array_map('trim', $fruit);


The above example will print the following:


array(3) {
  string(5) "apple"
  string(6) "banana"
  string(5) "mango"


In conclusion, we discussed the PHP trim Function. You can read more about it on PHP Official Documentation. Additionally, you can learn about more PHP String Functions on Concatly.

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