我有一个用PHP编写的代码片段,它从数据库中提取一个文本块,并将其发送到网页上的一个小部件。原文可以是一篇很长的文章,也可以是一两个短句;但是对于这个小部件,我不能显示超过200个字符。我可以使用substr()在200个字符处切断文本,但结果将在单词中间切断——我真正想要的是在200个字符前的最后一个单词的末尾切断文本。


当前回答

Keep in mind whenever you're splitting by "word" anywhere that some languages such as Chinese and Japanese do not use a space character to split words. Also, a malicious user could simply enter text without any spaces, or using some Unicode look-alike to the standard space character, in which case any solution you use may end up displaying the entire text anyway. A way around this may be to check the string length after splitting it on spaces as normal, then, if the string is still above an abnormal limit - maybe 225 characters in this case - going ahead and splitting it dumbly at that limit.

当涉及到非ascii字符时,还有一个类似的警告;包含它们的字符串可能会被PHP的标准strlen()解释为比实际更长,因为单个字符可能占用两个或更多字节,而不是一个字节。如果你只是使用strlen()/substr()函数来分割字符串,你可能会在字符中间分割字符串!如果有疑问,mb_strlen()/mb_substr()更简单一些。

其他回答

下面是基于@Cd-MaN方法的函数。

function shorten($string, $width) {
  if(strlen($string) > $width) {
    $string = wordwrap($string, $width);
    $string = substr($string, 0, strpos($string, "\n"));
  }

  return $string;
}

Keep in mind whenever you're splitting by "word" anywhere that some languages such as Chinese and Japanese do not use a space character to split words. Also, a malicious user could simply enter text without any spaces, or using some Unicode look-alike to the standard space character, in which case any solution you use may end up displaying the entire text anyway. A way around this may be to check the string length after splitting it on spaces as normal, then, if the string is still above an abnormal limit - maybe 225 characters in this case - going ahead and splitting it dumbly at that limit.

当涉及到非ascii字符时,还有一个类似的警告;包含它们的字符串可能会被PHP的标准strlen()解释为比实际更长,因为单个字符可能占用两个或更多字节,而不是一个字节。如果你只是使用strlen()/substr()函数来分割字符串,你可能会在字符中间分割字符串!如果有疑问,mb_strlen()/mb_substr()更简单一些。

我有一个函数,它几乎可以做你想要的,如果你做一些编辑,它将完全适合:

<?php
function stripByWords($string,$length,$delimiter = '<br>') {
    $words_array = explode(" ",$string);
    $strlen = 0;
    $return = '';
    foreach($words_array as $word) {
        $strlen += mb_strlen($word,'utf8');
        $return .= $word." ";
        if($strlen >= $length) {
            $strlen = 0;
            $return .= $delimiter;
        }
    }
    return $return;
}
?>

我相信这是最简单的方法:

$lines = explode('♦♣♠',wordwrap($string, $length, '♦♣♠'));
$newstring = $lines[0] . ' &bull; &bull; &bull;';

我正在使用特殊字符分割文本并剪切它。

你可以用这个:

function word_shortener($text, $words=10, $sp='...'){

  $all = explode(' ', $text);
  $str = '';
  $count = 1;

  foreach($all as $key){
    $str .= $key . ($count >= $words ? '' : ' ');
    $count++;
    if($count > $words){
      break;
    }
  }

  return $str . (count($all) <= $words ? '' : $sp);

}

例子:

word_shortener("Hello world, this is a text", 3); // Hello world, this...
word_shortener("Hello world, this is a text", 3, ''); // Hello world, this
word_shortener("Hello world, this is a text", 3, '[read more]'); // Hello world, this[read more]

Edit

工作原理:

1. 从输入文本中打开空格:

$all = explode(' ', $text);

例如,如果$text将是"Hello world",那么$all是一个带有爆炸值的数组:

“你好”,“世界”)

2. 对于每个单词:

选择展开文本中的每个元素:

foreach($all as $key){...

将当前单词($key)附加到$str,如果它是最后一个单词,则添加空格:

$str .= $key . ($count >= $words ? '' : ' ');

然后给$count加上1,检查它是否大于max limit($words)打破循环:

if($count > $words){
   break;
}

只有当最终文本小于输入文本时,才返回$str和分隔符($sp):

return $str . (count($all) <= $words ? '' : $sp);