说实话，如果你想要这样的东西

preg_replace('/\n+|\t+|\s+/',' ',$string);

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;

这是我要用的:

a.确保使用双引号，例如:

$row['message'] = "This is   a Text \n and so on \t     Text text.";

b.删除多余的空白，使用:

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

它可能不是最快的解决方案，但我认为它需要最少的代码，而且应该可以工作。不过，我从未使用过mysql，所以我可能是错的。

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.

<?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);

<?php
$str = "This is  a string       with
spaces, tabs and newlines present";

$stripped = preg_replace(array('/\s{2,}/', '/[\t\n]/'), ' ', $str);

echo $str;
echo "\n---\n";
echo "$stripped";
?>

这个输出

This is  a string   with
spaces, tabs and newlines present
---
This is a string with spaces, tabs and newlines present