Question

我想出了这个函数，它将给定的字符串截断为给定的字数或给定的字符数，无论是更短的字符。然后，在字符数或字数限制之后切断所有内容后，它会在字符串后附加一个“...”。

如何从字符串中间删除字符/单词并将其替换为“...”而不是用“...”替换末尾的字符/单词？

这是我的代码：

function truncate($input, $maxWords, $maxChars){
    $words = preg_split('/\s+/', $input);
    $words = array_slice($words, 0, $maxWords);
    $words = array_reverse($words);

    $chars = 0;
    $truncated = array();

    while(count($words) > 0)
    {
        $fragment = trim(array_pop($words));
        $chars += strlen($fragment);

        if($chars > $maxChars){
            if(!$truncated){
                $truncated[]=substr($fragment, 0, $maxChars - $chars);
            }
            break;
        }

        $truncated[] = $fragment;
    }

    $result = implode($truncated, ' ');

    return $result . ($input == $result ? '' : '...');
}

例如，如果调用truncate('the quick brown fox jumps over the lazy dog', 8, 16);，则16个字符更短，因此将发生截断。因此，'狐狸跳过懒狗'将被删除，'...'将被追加。

但是，相反，我怎么能有一半的字符限制来自字符串的开头，一半来自字符串的结尾，中间删除的内容被'...'替换？所以，我想要回来的字符串，其中一个案例是：'quic ...懒狗'。

Answer 1

$text = 'the quick brown fox jumps over the lazy dog';
$textLength = strlen($text);
$maxChars = 16;

$result = substr_replace($text, '...', $maxChars/2, $textLength-$maxChars);

$结果现在是：

the quic...lazy dog

Answer 2

这不会改变短于$maxChars的输入，并会考虑替换...的长度：

function str_truncate_middle($text, $maxChars = 25, $filler = '...')
{
    $length = strlen($text);
    $fillerLength = strlen($filler);

    return ($length > $maxChars)
        ? substr_replace($text, $filler, ($maxChars - $fillerLength) / 2, $length - $maxChars + $fillerLength)
        : $text;
}

Answer 3

以下是我最终使用的内容：

/**
 * Removes characters from the middle of the string to ensure it is no more
 * than $maxLength characters long.
 *
 * Removed characters are replaced with "..."
 *
 * This method will give priority to the right-hand side of the string when
 * data is truncated.
 *
 * @param $string
 * @param $maxLength
 * @return string
 */
function truncateMiddle($string, $maxLength)
{
    // Early exit if no truncation necessary
    if (strlen($string) <= $maxLength) return $string;

    $numRightChars = ceil($maxLength / 2);
    $numLeftChars = floor($maxLength / 2) - 3; // to accommodate the "..."

    return sprintf("%s...%s", substr($string, 0, $numLeftChars), substr($string, 0 - $numRightChars));
}

对于我的用例，字符串的右侧包含更多有用的信息，因此这种方法偏向于从左半部分中取出字符。

截断字符串，但删除字符串的中间而不是结束

3 个答案: