<p><span class="ql-size-large">// 兼容ie8以下获取className</span></p><p><span class="ql-size-large">var forms = {</span></p><p><span class="ql-size-large"> getElementsByClassName: function(str){</span></p><p><span class="ql-size-large"> var searchClass = str.searchClass;//存储要查找的类名</span></p><p><span class="ql-size-large"> var node = str.node|| document;//存储要查找的范围</span></p><p><span class="ql-size-large"> var tag = str.tag||'*';//存储一定范围内要查找的标签</span></p><p><span class="ql-size-large"> var result = [];</span></p><p><span class="ql-size-large"> // 判断浏览器不支持getElementsByClassName方法</span></p><p><span class="ql-size-large"> if(document.getElementsByClassName){ //如果浏览器支持</span></p><p><span class="ql-size-large"> var nodes = node.getElementsByClassName(searchClass);</span></p><p><span class="ql-size-large"> if(tag !=='*'){</span></p><p><span class="ql-size-large"> for(var i=0;node=nodes[i++];){</span></p><p><span class="ql-size-large"> if(node.tagName === tag.toUpperCase()){</span></p><p><span class="ql-size-large"> result.push(node);</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large"> }else{</span></p><p><span class="ql-size-large"> result = nodes;</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large"> return result;</span></p><p><span class="ql-size-large"> }else{ //使IE8以下的浏览器能够支持该属性</span></p><p><span class="ql-size-large"> var els = node.getElementsByTagName(tag);</span></p><p><span class="ql-size-large"> var elsLen = els.length;</span></p><p><span class="ql-size-large"> var i,j;</span></p><p><span class="ql-size-large"> var pattern = new RegExp("(^|\\s)" + searchClass + "(\\s|$)");</span></p><p><span class="ql-size-large"> for(i = 0,j=0;i&lt;elsLen;i++){</span></p><p><span class="ql-size-large"> if(pattern.test(els[i].className)){&nbsp;//检测正则表达式</span></p><p><span class="ql-size-large"> result[j] = els[i];</span></p><p><span class="ql-size-large"> j++;</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large"> return result;</span></p><p><span class="ql-size-large"> }&nbsp;</span></p><p><span class="ql-size-large"> }</span></p><p><span class="ql-size-large">}</span></p>