What is trim used for in php?

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

trim — Strip whitespace (or other characters) from the beginning and end of a string

Description

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

• " " (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.

Parameters

The string that will be trimmed.

Optionally, the stripped characters can also be specified using the characters parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

Return Values

The trimmed string.

Examples

Example #1 Usage example of trim()

$text

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); 
}$fruit = array('apple','banana ', ' cranberry ');
var_dump($fruit);array_walk($fruit, 'trim_value');
var_dump($fruit);?>

The above example will output:

array(3) {
  [0]=>
  string(5) "apple"
  [1]=>
  string(7) "banana "
  [2]=>
  string(11) " cranberry "
}
array(3) {
  [0]=>
  string(5) "apple"
  [1]=>
  string(6) "banana"
  [2]=>
  string(9) "cranberry"
}

Notes

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