以下是我的解决方案，与其他建议相比有一些改进:

String.prototype.truncate = function(){
    var re = this.match(/^.{0,25}[\S]*/);
    var l = re[0].length;
    var re = re[0].replace(/\s$/,'');
    if(l < this.length)
        re = re + "&hellip;";
    return re;
}

// "This is a short string".truncate();
"This is a short string"

// "Thisstringismuchlongerthan25characters".truncate();
"Thisstringismuchlongerthan25characters"

// "This string is much longer than 25 characters and has spaces".truncate();
"This string is much longer&hellip;"

It:

在25之后的第一个空格上截断 字符 扩展JavaScript字符串对象， 因此它可以用于(并链接到) 任何字符串。 如果截断将修剪字符串 结果在一个尾随空间中; 是否添加unicode hellip实体 (省略号)如果截断的字符串长于25个字符

以下是我的解决方案，与其他建议相比有一些改进:

String.prototype.truncate = function(){
    var re = this.match(/^.{0,25}[\S]*/);
    var l = re[0].length;
    var re = re[0].replace(/\s$/,'');
    if(l < this.length)
        re = re + "&hellip;";
    return re;
}

// "This is a short string".truncate();
"This is a short string"

// "Thisstringismuchlongerthan25characters".truncate();
"Thisstringismuchlongerthan25characters"

// "This string is much longer than 25 characters and has spaces".truncate();
"This string is much longer&hellip;"

It:

在25之后的第一个空格上截断 字符 扩展JavaScript字符串对象， 因此它可以用于(并链接到) 任何字符串。 如果截断将修剪字符串 结果在一个尾随空间中; 是否添加unicode hellip实体 (省略号)如果截断的字符串长于25个字符

如果你想用css而不是JavaScript;

.textShortDesc { /*Here we have determined the max number of lines.*/
    display: block; /* or inline-block */
    -o-text-overflow: ellipsis; /* Opera < 11*/
    text-overflow: ellipsis; /* IE, Safari (WebKit), Opera >= 11, FF > 6 */
    word-wrap: break-word;
    overflow: hidden;
    max-height: 2em; /*max-height/line-height=rowCount */
    line-height: 1em;
}

大多数现代Javascript框架(JQuery, Prototype等)都有一个附加在String上的实用函数来处理这个问题。

下面是Prototype中的一个例子:

'Some random text'.truncate(10);
// -> 'Some ra...'

这似乎是您希望其他人处理/维护的功能之一。我会让框架来处理它，而不是编写更多的代码。

聪明的地方:D

//My Huge Huge String let tooHugeToHandle = `It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).` //Trim Max Length const maxValue = 50 // The barber. const TrimMyString = (string, maxLength, start = 0) => { //Note - `start` is if I want to start after some point of the string if (string.length > maxLength) { let trimmedString = string.substr(start, maxLength) return ( trimmedString.substr( start, Math.min(trimmedString.length, trimmedString.lastIndexOf(' ')) ) + ' ...' ) } return string } console.log(TrimMyString(tooHugeToHandle, maxValue))

在我看来，C_harm的答案是最好的。请注意，如果你想使用

"My string".truncate(n)

您将不得不使用regexp对象构造函数而不是文字。此外，在转换\S时还必须转义它。

String.prototype.truncate =
    function(n){
        var p  = new RegExp("^.{0," + n + "}[\\S]*", 'g');
        var re = this.match(p);
        var l  = re[0].length;
        var re = re[0].replace(/\s$/,'');

        if (l < this.length) return re + '&hellip;';
    };