PHP ltrim() Function: Removing Leading Characters from Strings

The PHP ltrim() function removes whitespace or specified characters from the beginning of a string.

Syntax: string ltrim(string $str [, string $character_mask]) Parameters

$str : the input string.

$character_mask (optional): a list of characters to strip; ranges can be defined with ...

Return value : the trimmed string.

If $character_mask is omitted, ltrim() removes the following characters by default: space ( " "), tab ( "\t"), newline ( "\n"), carriage return ( "\r"), NUL byte ( "\0"), and vertical tab ( "\x0B").

Example usage :

<?php
$text = "\t\tThese are a few words :) ...  ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";

var_dump($text, $binary, $hello);
$trimmed = ltrim($text);
var_dump($trimmed);

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

$clean = ltrim($binary, "\x00..\x1F");
var_dump($clean);
?>

The first var_dump shows the original strings; after calling ltrim($text) the leading tabs are removed. Using a custom mask removes spaces, tabs, and periods. The final example demonstrates stripping ASCII control characters (0–31) from $binary.