Question

我在变量中有以下字符串。

Stack Overflow is as frictionless and painless to use as we could make it.

我想从上面的行中获取前28个字符，所以通常如果我使用substr那么它会给我Stack Overflow is as frictio这个输出，但我希望输出为：

Stack Overflow is as...

PHP中是否有任何预制函数可以这样做，或者请在PHP中为我提供此代码？

编辑：

我想要字符串中的总共28个字符而不会破坏一个单词，如果它会使我的字符少于28而不会断言，那就没问题了。

Answer 1

你可以使用wordwrap()功能，然后在换行符上爆炸并采取第一部分：

$str = wordwrap($str, 28);
$str = explode("\n", $str);
$str = $str[0] . '...';

Answer 2

来自AlfaSky：

function addEllipsis($string, $length, $end='…')
{
    if (strlen($string) > $length)
    {
        $length -= strlen($end);
        $string  = substr($string, 0, $length);
        $string .= $end;
    }

    return $string;
}

来自Elliott Brueggeman's blog的另一个更具特色的实现：

/**
 * trims text to a space then adds ellipses if desired
 * @param string $input text to trim
 * @param int $length in characters to trim to
 * @param bool $ellipses if ellipses (...) are to be added
 * @param bool $strip_html if html tags are to be stripped
 * @return string 
 */
function trim_text($input, $length, $ellipses = true, $strip_html = true) {
    //strip tags, if desired
    if ($strip_html) {
        $input = strip_tags($input);
    }

    //no need to trim, already shorter than trim length
    if (strlen($input) <= $length) {
        return $input;
    }

    //find last space within length
    $last_space = strrpos(substr($input, 0, $length), ' ');
    $trimmed_text = substr($input, 0, $last_space);

    //add ellipses (...)
    if ($ellipses) {
        $trimmed_text .= '...';
    }

    return $trimmed_text;
}

（谷歌搜索：“php trim ellipses”）

Answer 3

这是你可以做到的一种方式：

$str = "Stack Overflow is as frictionless and painless to use as we could make it.";

$strMax = 28;
$strTrim = ((strlen($str) < $strMax-3) ? $str : substr($str, 0, $strMax-3)."...");

//or this way to trim to full words
$strFull = ((strlen($str) < $strMax-3) ? $str : strrpos(substr($str, 0, $strMax-3),' ')."...");

Answer 4

这是我所知道的最简单的解决方案......

substr($string,0,strrpos(substr($string,0,28),' ')).'...';

Answer 5

这是最简单的方法：

<?php 
$title = "this is the title of my website!";
$number_of_characters = 15;
echo substr($title, 0, strrpos(substr($title, 0, $number_of_characters), " "));
?>

Answer 6

尝试：

$string='Stack Overflow is as frictionless and painless to use as we could make it.';
$n=28;
$break=strpos(wordwrap($string, $n,'<<||>>'),'<<||>>');
print substr($string,0,($break==0?strlen($string):$break)).(strlen($string)>$n?'...':'');

$string='Stack Overflow';
$n=28;
$break=strpos(wordwrap($string, $n,'<<||>>'),'<<||>>');
print substr($string,0,($break==0?strlen($string):$break)).(strlen($string)>$n?'...':'');

Answer 7

我会使用string tokenizer将字符串拆分成如下字样：

$string = "Stack Overflow is as frictionless and painless to use as we could make it.";
$tokenized_string = strtok($string, " ");

然后你可以随心所欲地抽出单词。

编辑：Greg有更好，更优雅的方式做你想做的事。我会使用他的wordwrap（）解决方案。

Answer 8

您可以使用wordwrap。

string wordwrap  ( string $str  [, int $width= 75  [, string $break= "\n"  [, bool $cut= false  ]]] )

-

function firstNChars($str, $n) {
  return array_shift(explode("\n", wordwrap($str, $n)));
}

echo firstNChars("bla blah long string", 25) . "...";

免责声明：没有测试。

另外，如果你的字符串包含\n s，它可能会更早被破坏。

Answer 9

function truncate( $string, $limit, $break=" ", $pad="...") {

 // return with no change if string is shorter than $limit
 if(strlen($string) <= $limit){
    return $string;
 }

 $string = substr($string, 0, $limit);
 if(false !== ($breakpoint = strrpos($string, $break))){
    $string = substr($string, 0, $breakpoint);
 }
 return $string . $pad;
}

Answer 10

如果您的字符串包含html标记，＆amp; nbsp和多个空格，则可能会出现问题。以下是我用来处理所有事情的内容：

function LimitText($string,$limit,$remove_html=0){
    if ($remove_html==1){$string=strip_tags($string);}
    $newstring = preg_replace("/(?:\s|&nbsp;)+/"," ",$string, -1); // replace &nbsp with space
    $newstring = preg_replace(array('/\s{2,}/','/[\t\n]/'),' ',$newstring); // replace duplicate spaces
    if (strlen($newstring)<=$limit) { return $newstring; } // ensure length is more than $limit
    $newstring = substr($newstring,0,strrpos(substr($newstring,0,$limit),' '));
    return $newstring;
}

用法：

$string = 'My wife is jealous of stackoverflow';
echo LimitText($string,20);
// My wife is jealous

使用html：

$string = '<div><p>My wife is jealous of stackoverflow</p></div>';
echo LimitText($string,20,1);
// My wife is jealous

Answer 11

这是为我工作的完美

function WordLimt($Keyword,$WordLimit){

    if (strlen($Keyword)<=$WordLimit) { return $Keyword; }
    $Keyword= substr($Keyword,0,strrpos(substr($Keyword,0,$WordLimit),' '));
    return $Keyword;
}

echo WordLimt($MyWords,28);

// OutPut : Stack Overflow is as

它会调整并在最后一个空格上打破而不会被切断...

Answer 12

为什么不尝试将它爆炸并获得数组的前4个元素？

Answer 13

substr("some string", 0, x);

来自PHP Manual

如何从字符串中获取第一个x字符，而不切断最后一个字？

13 个答案: