(PHP 4, PHP 5, PHP 7)
trim — 去除字符串首尾处的空白字符(或者其他字符)
定义和用法
trim() 函数移除字符串两侧的空白字符或其他预定义字符。
相关函数:
语法
trim(string,charlist)
参数 | 描述 |
---|---|
string | 必需。规定要检查的字符串。 |
charlist |
可选。规定从字符串中删除哪些字符。如果被省略,则移除以下所有字符:
|
范例
Example #1 trim() 使用范例
<?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);
// 清除 $binary 首位的 ASCII 控制字符
// (包括 0-31)
$clean = trim($binary, "\x00..\x1F");
var_dump($clean);
?>
结果:
string(32) " These are a few words :) ... "
string(16) " Example string
"
string(11) "Hello World"
string(28) "These are a few words :) ..."
string(24) "These are a few words :)"
string(5) "o Wor"
string(14) "Example string"
Example #2 使用 trim() 清理数组值
<?php
function trim_value(&$value)
{
$value = trim($value);
}
$fruit = array('apple','banana ', ' cranberry ');
var_dump($fruit);
array_walk($fruit, 'trim_value');
var_dump($fruit);
?>
结果:
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" }