How to replace whitespace in php

How to replace whitespace in php: first remove the starting and ending whitespace through the "trim($str)" method; then use "preg_replace" to remove the whitespace that is crowded with others; finally use regular expressions to remove non-space blank and replace it with a space.

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php replaces and filters all whitespace characters and spaces Example

The trim function that comes with PHP can only replace the spaces at the left and right ends. I feel that it is not very useful in some cases. If you want to filter out all the whitespace characters in a string (spaces , full-width spaces, newlines, etc.), then we can write a filter function ourselves.

Everyone who has learned the str_replace function in php knows that it can be replaced in batches, so we can use the following source code to replace and filter all whitespace characters in a string.

php source code reference:

$str = 'jkgsd
gsgsdgs  gsdg gsd';
echo myTrim($str);
function myTrim($str)
{
 $search = array(" ","　","\n","\r","\t");
 $replace = array("","","","","");
 return str_replace($search, $replace, $str);
}
?>
运行代码，页面输出：jkgsdgsgsdgsgsdggsd，完美实现了我们想要的效果。
完成这些可以使用PHP的正则表达式来完成
下例可以去除额外Whitespace
$str = " This line  contains\tliberal \r\n use of   whitespace.\n\n";
// First remove the leading/trailing whitespace
//去掉开始和结束的空白
$str = trim($str);
// Now remove any doubled-up whitespace
//去掉跟随别的挤在一块的空白
$str = preg_replace('/\s(?=\s)/', '', $str);
// Finally, replace any non-space whitespace, with a space
//最后，去掉非space 的空白，用一个空格代替
$str = preg_replace('/[\n\r\t]/', ' ', $str);
// Echo out: 'This line contains liberal use of whitespace.'
echo "
{$str}
";
?>
这个例子剥离多余的空白字符
$str = 'foo o';
$str = preg_replace('/\s\s+/', '', $str);
// 将会改变为'foo o'
echo $str;
?>

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