php man page for trim

TRIM(3) 								 1								   TRIM(3)

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

SYNOPSIS
       string trim (string  $str, [string  $character_mask = " 0r B"])

DESCRIPTION
	This  function	returns  a  string with whitespace stripped from the beginning and end of $str. Without the second parameter, trim(3) will
       strip these characters:

	      o " " (ASCII
		32 ( 0x20)), an ordinary space.

	      o "	" (ASCII
		9 ( 0x09)), a tab.

	      o "
" (ASCII
		10 ( 0x0A)), a new line (line feed).

	      o "
" (ASCII
		13 ( 0x0D)), a carriage return.

	      o "" (ASCII
		0 ( 0x00)), the NUL-byte.

	      o "x0B" (ASCII
		11 ( 0x0B)), a vertical tab.

PARAMETERS
	      o $str
		- The string that will be trimmed.

	      o $character_mask
		- Optionally, the stripped characters can also be specified using the $character_mask 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(3)

	      <?php

	      $text   = "		These are a few words :) ...  ";
	      $binary = "x09Example stringx0A";
	      $hello  = "Hello World";
	      var_dump($text, $binary, $hello);

	      print "
";

	      $trimmed = trim($text);
	      var_dump($trimmed);

	      $trimmed = trim($text, " 	.");
	      var_dump($trimmed);

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

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

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

	      ?>

	      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(3)

	      <?php
	      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(3)  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(3), rtrim(3), str_replace(3).

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