trim
(PHP 3, PHP 4, PHP 5)
trim -- Strip whitespace (or other characters) from the beginning and end of a string
说明
string
trim ( string str [, string charlist] )
This function returns a string with whitespace stripped from the
beginning and end of str.
Without the second parameter,
trim() 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.
参数
str
The string that will be trimmed.
charlist
Optionally, the stripped characters can also be specified using
the charlist parameter.
Simply list all characters that you want to be stripped. With
.. you can specify a range of characters.
范例
例 1. Usage example of trim()
<?php
$text = "\t\tThese are a few words :) ... ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";
var_dump($text, $binary, $hello);
print "\n";
$trimmed = trim($text);
var_dump($trimmed);
$trimmed = trim($text, " \t.");
var_dump($trimmed);
$trimmed = trim($hello, "Hdle");
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($clean);
?>
|
上例将输出： string(32) " These are a few words :) ... "
string(16) " Example string
"
string(11) "Hello World"
string(28) "These are a few words :) ..."
string(24) "These are a few words :)"
string(5) "o Wor"
string(14) "Example string" |
|
例 2. Trimming array values with trim()
<?php
function trim_value(&$value)
{
$value = trim($value);
}
$fruit = array('apple','banana ', ' cranberry ');
var_dump($fruit);
array_walk($fruit, 'trim_value');
var_dump($fruit);
?>
|
上例将输出： 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"
} |
|