javascript - 将多个 替换为一个

Question

我如何使用JavaScript来检测

<br>
<br>
<br>

成为一个

<br>

?

我试过:

jQuery('body').html().replace(/(\<br\>\r\n){3, }/g,"\n");

但这对我不起作用。

Answer 1

CSS 解决方案

如果要禁用多个<br>的效果在页面上，您可以通过 CSS 来完成，而无需使用 JavaScript:

br + br { display: none; }

• 检查 jsFiddle demo .

但是，当您使用标签时，此方法非常理想，如下所示:

<div>Text</div><br /><br /><br />
<div>Text</div><br /><br /><br />
<div>Text</div><br /><br /><br />

在其他情况下，像这样:

Hello World<br />   <br />
Hello World<br />   <br />
Hello World<br />   <br />

它会失败(因为 CSS 传递文本节点)。相反，请使用 JavaScript 解决方案。

---

JavaScript 解决方案

// It's better to wait for document ready instead of window.onload().
window.onload = function () {
    // Get all `br` tags, defined needed variables
    var br = document.getElementsByTagName('br'),
        l = br.length,
        i = 0,
        nextelem, elemname, include;
        
    // Loop through tags
    for (i; i < l - 1; i++) {
        // This flag indentify we should hide the next element or not
        include = false;
        
        // Getting next element
        nextelem = br[i].nextSibling;
        
        // Getting element name
        elemname = nextelem.nodeName.toLowerCase();
        
        // If element name is `br`, set the flag as true.
        if (elemname == 'br') {
            include = true;
        }
        
        // If element name is `#text`, we face text node
        else if (elemname == '#text') {
            // If text node is only white space, we must pass it.
            // This is because of something like this: `<br />   <br />`
            if (! nextelem.data.replace(/\s+/g, '').length) {
                nextelem = br[i+1];
                include = true;
            }
        }
        
        // If the element is flagged as true, hide it
        if (include) {
            nextelem.style.display = 'none';
        }
    }
};

• 检查 jsFiddle demo .