如何添加<；br>'；如果空格前的单词超过3个字符，则三个句点后的s

$string = "Mr.Bean said: It must be great to know PHP. He added that IP 1.2.3.4 is the best IP address one could own. Mrs. Walter. Today is a wonderful day. Tomorrow, it will rain. This is really just some random text. Did you hear this singing bird? I visited Berlin yesterday. It was raining and Mr. Bean said hello. Mrs. Bean was also there. They have two kids.";
function splitString($str)
{
    //look for 2 full stops, then another full stop with at least 4 word characters in front of it
    preg_match_all('#(.+?'..+?'..+?'w{4,}'.)#',$str,$matches);
    return implode('<br><br>',array_map('trim',$matches[1]));
}
echo splitString($string);

输出：

Mr.Bean said: It must be great to know PHP. He added that IP 1.2.3.4 is the best IP address one could own. Mrs. Walter.
Today is a wonderful day. Tomorrow, it will rain. This is really just some random text.
Did you hear this singing bird? I visited Berlin yesterday. It was raining and Mr. Bean said hello.
Mrs. Bean was also there. They have two kids.

确保在完全停止后立即没有内容的新版本：

$string = " Bill Price reveals his new method for playing the diatonic harmonica, whereby anyone can convert their ordinary ten-hole diatonic harmonicas into lead instruments. Coupling is a patented method; guaranteed to expand the harmonica's range and over-all capability. The major key diatonic coupling formula for this method is disclosed at: http://example.com/. You'll enjoy samples from Bill's unique ten-song CD, Taking the Lead. This CD displays dynamic possibilities available when pairing/coupling two diatonic harmonicas together. The result is truly astonishing! The formula is free for visiting example.com. The CD is only $8, plus it can be used as a tutorial for learning the Coupling Method.";
function splitString($str)
{
    preg_match_all('#(.+?'..+?'..+?'w{4,}'.($| ))#',$str,$matches);
    return implode('<br><br>',array_map('trim',$matches[1]));
}
echo splitString($string);

输出：

Bill Price reveals his new method for playing the diatonic harmonica, whereby anyone can convert their ordinary ten-hole diatonic harmonicas into lead instruments. Coupling is a patented method; guaranteed to expand the harmonica's range and over-all capability. The major key diatonic coupling formula for this method is disclosed at: http://example.com/. You'll enjoy samples from Bill's unique ten-song CD, Taking the Lead.
This CD displays dynamic possibilities available when pairing/coupling two diatonic harmonicas together. The result is truly astonishing! The formula is free for visiting example.com. The CD is only $8, plus it can be used as a tutorial for learning the Coupling Method.

这可以完成您想要的操作，但输出与您期望的不同（Look ma，no regex）：

function splitString($string) {
    $pieces = explode(".", $string); // Split string into array at each "."
    $count = count($pieces);
    $tally = 0;
    for ($i = 0; $i < $count - 1; $i++) { // Loop through each piece ignoring the last as it doesn't make sense to put a "<br />" after it.
       $piece = $pieces[$i];
       $words = explode(" ", $piece);
       if (strlen(trim($words[count($words)-1])) > 3) { // Check whether the last word in this piece is greater than 3 characters long
          $tally++;
          if ($tally % 3 == 0) { 
            $pieces[$i + 1] = '<br />' . ltrim($pieces[$i + 1]); // Prepend "<br />" to next piece and remove any preceding whitespace
          }
       }
       $pieces[$i] .= ".";
    }
    return implode($pieces); // Put pieces into a string
}

输出：

Mr.Bean said: It must be great to know PHP. He added that IP 1.2.3.4 is the best IP address one could own. Mrs. Walter. Today is a wonderful day. Tomorrow, it will rain. This is really just some random text.<br>Did you hear this singing bird? I visited Berlin yesterday. It was raining and Mr. Bean said hello. Mrs. Bean was also there.<br>They have two kids.

它检测到以下单词符合您的标准：

• Walter
• 雨
• 文本
• 昨天
• 你好
• 那里
• 孩子

试试这个：

$string=<lt<EOD
憨豆先生说：一定很棒。。。了解PHP。他补充说，IP 1.2.3.4是最好的IP地址。沃尔特夫人。今天是美好的一天。明天会下雨。这真的只是一些随机的文本。你听到这只鸟唱歌了吗？我昨天访问了柏林。。。当时正在下雨，憨豆先生打招呼。憨豆夫人也在那里。。。他们有两个孩子。EOD；

echo str_replace（"…"，"
"，$string）；

如果您想了解更多信息：http://php.net/manual/en/function.str-replace.php

为了获得最佳实践，请尝试使用Heredoc语法来声明变量（$string）：http://php.net/manual/en/language.types.string.php