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(PHP 4, PHP 5, PHP 7, PHP 8)

trimStrip whitespace (or other characters) from the beginning and end of a string


trim(string $string, string $characters = " \n\r\t\v\x00"): string

This function returns a string with whitespace stripped from the beginning and end of string. Without the second parameter, trim() will strip these characters:

  • " " (ASCII 32 (0x20)), an ordinary space.
  • "\t" (ASCII 9 (0x09)), a tab.
  • "\n" (ASCII 10 (0x0A)), a new line (line feed).
  • "\r" (ASCII 13 (0x0D)), a carriage return.
  • "\0" (ASCII 0 (0x00)), the NUL-byte.
  • "\v" (ASCII 11 (0x0B)), a vertical tab.



The string that will be trimmed.


Optionally, the stripped characters can also be specified using the characters parameter. Simply list all characters that need to be stripped. With .. it is possible to specify an incrementing range of characters.

Return Values

The trimmed string.


Example #1 Usage example of trim()


= "\t\tThese are a few words :) ... ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";
var_dump($text, $binary, $hello);


$trimmed = trim($text);

$trimmed = trim($text, " \t.");

$trimmed = trim($hello, "Hdle");

$trimmed = trim($hello, 'HdWr');

// trim the ASCII control characters at the beginning and end of $binary
// (from 0 to 31 inclusive)
$clean = trim($binary, "\x00..\x1F");


The above example will output:

string(32) "        These are a few words :) ...  "
string(16) "    Example string
string(11) "Hello World"

string(28) "These are a few words :) ..."
string(24) "These are a few words :)"
string(5) "o Wor"
string(9) "ello Worl"
string(14) "Example string"

Example #2 Trimming array values with trim()

function trim_value(&$value)
$value = trim($value);

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

array_walk($fruit, 'trim_value');


The above example will output:

array(3) {
  string(5) "apple"
  string(7) "banana "
  string(11) " cranberry "
array(3) {
  string(5) "apple"
  string(6) "banana"
  string(9) "cranberry"


Note: Possible gotcha: removing middle characters

Because trim() trims characters from the beginning and end of a string, it may be confusing when characters are (or are not) removed from the middle. trim('abc', 'bad') removes both 'a' and 'b' because it trims 'a' thus moving 'b' to the beginning to also be trimmed. So, this is why it "works" whereas trim('abc', 'b') seemingly does not.

See Also

  • ltrim() - Strip whitespace (or other characters) from the beginning of a string
  • rtrim() - Strip whitespace (or other characters) from the end of a string
  • str_replace() - Replace all occurrences of the search string with the replacement string

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User Contributed Notes 2 notes

pcoates at yukon1000 dot com
1 year ago
note there is a behaviour change in php 8

You used to be able to say:
$p1 = trim($_POST['p1']);
This will now throw deprecated warnings if parameter p1 is not set. It is better to say:
$p1 = trim($_POST['p1']??'');
$p1 = isset($_POST['p1']) ? trim($_POST['p1']) : null;
$p1 = isset($_POST['p1']) ? trim($_POST['p1']) : '';
gwyneth dot llewelyn at gwynethllewelyn dot net
1 year ago
Note that trim() is not aware of Unicode points that represent whitespace (e.g., in the General Punctuation block), except, of course, for the ones mentioned in this page.

There is no Unicode-specific trim function in PHP at the time of writing (July 2023), but you can try some examples of trims using multibyte strings posted on the comments for the mbstring extension:
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