简化为一个函数:

function removeWhiteSpace($text)
{
    $text = preg_replace('/[\t\n\r\0\x0B]/', '', $text);
    $text = preg_replace('/([\s])\1+/', ' ', $text);
    $text = trim($text);
    return $text;
}

基于丹尼尔·奥尼尔的答案。

没有preg_replace ()

$str = "This is   a Text \n and so on \t     Text text.";
$str = str_replace(["\r", "\n", "\t"], " ", $str);
while (strpos($str, "  ") !== false)
{
    $str = str_replace("  ", " ", $str);
}
echo $str;

你需要:

$ro = preg_replace('/\s+/', ' ', $row['message']);

您正在使用的\s\s+表示空格(空格、制表符或换行符)后面跟着一个或多个空格。这实际上意味着用一个空格替换两个或多个空格。

你想要的是用单个空格替换一个或多个空格，所以你可以使用模式\s\s*或\s+(推荐)

你所需要的就是像下面这样运行它:

echo preg_replace('/\s{2,}/', ' ', "This is   a Text \n and so on \t     Text text."); // This is a Text and so on Text text.

$str='This is   a Text \n and so on Text text.';
print preg_replace("/[[:blank:]]+/"," ",$str);

<?php
#This should help some newbies
# REGEX NOTES FROM DANUEL
# I wrote these functions for my own php framework
# Feel Free to make it better
# If it gets more complicated than this. You need to do more software engineering/logic.
# (.)  // capture any character
# \1   // if it is followed by itself
# +    // one or more

class whitespace{

    static function remove_doublewhitespace($s = null){
           return  $ret = preg_replace('/([\s])\1+/', ' ', $s);
    }

    static function remove_whitespace($s = null){
           return $ret = preg_replace('/[\s]+/', '', $s );
    }

    static function remove_whitespace_feed( $s = null){
           return $ret = preg_replace('/[\t\n\r\0\x0B]/', '', $s);
    }

    static function smart_clean($s = null){
           return $ret = trim( self::remove_doublewhitespace( self::remove_whitespace_feed($s) ) );
    }
}
$string = " Hey   yo, what's \t\n\tthe sc\r\nen\n\tario! \n";
echo whitespace::smart_clean($string);