Strip whitespace (or other characters) from the beginning of a string

Descrierea

string ltrim ( string $str [, string $character_mask ] )

Strip whitespace (or other characters) from the beginning of a string.

Parametri

str: The input string.
character_mask: You can also specify the characters you want to strip, by means of the character_mask parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

Valorile întoarse

This function returns a string with whitespace stripped from the beginning of str. Without the second parameter, ltrim() 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.
"\x0B" (ASCII 11 (0x0B)), a vertical tab.

Istoria schimbărilor

Versiunea	Descriere
4.1.0	The `character_mask` parameter was added.

Exemple

Example #1 Usage example of ltrim()


<?php

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

print "\n";


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

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

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

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

?>

Exemplul de mai sus va afișa:

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

string(30) "These are a few words :) ...  "
string(30) "These are a few words :) ...  "
string(7) "o World"
string(15) "Example string
"

Vedeți de asemenea

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