(PHP 4, PHP 5)
ltrim — Strip whitespace (or other characters) from the beginning of a string
$str
[, string $charlist
] )Strip whitespace (or other characters) from the beginning of a string.
str
The input string.
charlist
You can also specify the characters you want to strip, by means of the
charlist parameter.
Simply list all characters that you want to be stripped. With
.. you can specify a range of characters.
This function returns a string with whitespace stripped from the
beginning of str.
Without the second parameter,
ltrim() will strip these characters:
| 版本 | 说明 |
|---|---|
| 4.1.0 |
The charlist parameter was added.
|
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);
?>
以上例程会输出：
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 "