下面的代码片段，“计算”span标签的宽度，如果它太长，就添加“…”，并减少文本长度，直到它适合它的父标签(或者直到它尝试了超过1000次)

CSS

div.places {
  width : 100px;
}
div.places span {
  white-space:nowrap;
  overflow:hidden;
}

HTML

<div class="places">
  <span>This is my house</span>
</div>
<div class="places">
  <span>And my house are your house</span>
</div>
<div class="places">
  <span>This placename is most certainly too wide to fit</span>
</div>

JavaScript(使用jQuery)

// loops elements classed "places" and checks if their child "span" is too long to fit
$(".places").each(function (index, item) {
    var obj = $(item).find("span");
    if (obj.length) {
        var placename = $(obj).text();
        if ($(obj).width() > $(item).width() && placename.trim().length > 0) {
            var limit = 0;
            do {
                limit++;
                                    placename = placename.substring(0, placename.length - 1);
                                    $(obj).text(placename + "...");
            } while ($(obj).width() > $(item).width() && limit < 1000)
        }
    }
});

我为此写了一个小工具。也许对某些人有用。它不需要jQuery也能工作。

https://github.com/schickling/calculate-size

用法:

var size = calculateSize("Hello world!", {
   font: 'Arial',
   fontSize: '12px'
});

console.log(size.width); // 65
console.log(size.height); // 14

小提琴:http://jsfiddle.net/PEvL8/

没有jQuery:

String.prototype.width = function (fontSize) {
    var el,
        f = fontSize + " px arial" || '12px arial';
    el = document.createElement('div');
    el.style.position = 'absolute';
    el.style.float = "left";
    el.style.whiteSpace = 'nowrap';
    el.style.visibility = 'hidden';
    el.style.font = f;
    el.innerHTML = this;
    el = document.body.appendChild(el);
    w = el.offsetWidth;
    el.parentNode.removeChild(el);
    return w;
}

// Usage
"MyString".width(12);

文本的宽度和高度可以通过clientWidth和clienttheight获得

var element = document.getElementById ("mytext");

var width = element.clientWidth;
var height = element.clientHeight;

确保style position属性被设置为absolute

element.style.position = "absolute";

不需要在div中，可以在p或span中

jQuery:

(function($) {

 $.textMetrics = function(el) {

  var h = 0, w = 0;

  var div = document.createElement('div');
  document.body.appendChild(div);
  $(div).css({
   position: 'absolute',
   left: -1000,
   top: -1000,
   display: 'none'
  });

  $(div).html($(el).html());
  var styles = ['font-size','font-style', 'font-weight', 'font-family','line-height', 'text-transform', 'letter-spacing'];
  $(styles).each(function() {
   var s = this.toString();
   $(div).css(s, $(el).css(s));
  });

  h = $(div).outerHeight();
  w = $(div).outerWidth();

  $(div).remove();

  var ret = {
   height: h,
   width: w
  };

  return ret;
 }

})(jQuery);

如果你可以安装一个包，并且你想要一个更权威或更精确的答案，你可以使用opentype.js(奇怪的是没有人提到这一点):

import { load } from "opentype.js";

const getWidth = async (text = "Hello World") => {
  const font = await load("path/to/some/font");
  const { x1, x2 } = font.getPath(text, 0, 0, 12).getBoundingBox();
  return x2 - x1;
};

当然，您希望每个字体只调用load一次，因此应该根据您的情况将该行拉出到更高的范围。

下面是一个代码沙盒，将OpenType方法与Canvas和DOM方法进行比较: https://codesandbox.io/s/measure-width-of-text-in-javascript-vctst2

在我的机器上，每个100个样品，典型的结果是:

女士的OpenType: 5 女士帆布:3 女士DOM: 4

我发现的另一个软件包是:https://github.com/sffc/word-wrappr