ClearOptionsAlt(FormName, SelectName) { document.forms[FormName].elements[SelectName].options.length = 0; } // Fast javascript function to clear all the options in an HTML select element // Provide the id of the select element // References to the old <select> object will become ...
for(var i=0;i<ctrl2.options.length;i++){ ctrl2.removeChild(ctrl2.options[i]);} 这一句，你取得是ctrl2.options.length，当你删除一项的时候，这个数值减一，所以不可能完全删除。在此基础上的修改是：for(var i=0;i<ctrl2.options.length;){ ctrl2.removeChild(ctrl2.options[i]);} ...
The standard way to clear all the options is to simply set theoptions.lengthproperty to zero. That function is listed below, and is fast enough when there are not that many options in the drop-down list (a.k.a. select boxes). This method is also the most browser-compatible. By clicki...
selectTag=document.getElementById("SelectBox");//获取select标记 colls=selectTag.options;//获取引用 //initSelectBox(); //自初始化select.options }; //使用随机数填充select.options functioninitSelectBox(){ varrandom=0; varoptionItem=null; varitem=null; if(colls.length>0&&isClearOption()){ c...
clearOptions(colls); } for(var i=0;i<OPTONLENGTH;i++){ random = Math.floor(Math.random()*9000)+1000; item = new Option(random,random); //通过Option()构造函数创建option对象 selectTag.options.add(item); //添加到options集合中
function clearOptionsV1(id){ document.getElementById(id).options.length = 0; } // 方式二 function clearOptionsV2(id){ document.getElementById(id).innerHTML = ""; } // 方式三 function clearOptionsV3(id){ var selectObj = document.getElementById(id); ...
select标记还有一个属性为selectedIndex,通过它可能获取当前选择的option索引:object.selectedIndex 1.清空options集合 functionoptionsClear(object) {var length = object.options.length; for(var i=length-1;i>=0;i--){ e.options.remove(i); } }
document.myform.dropcity.options[document.myform.dropcity.length] = new Option(subcity[i][1],subcity[i][2]);} } } </script> </head> <body> <form name="myform" method="post"> <select name="droppro" onChange="mychange(this.options[this.selectedIndex].value);"> <option...
</select> code: 一:javascript原生的方法 1:拿到select对象: var myselect=document.getElementById("test"); 2:拿到选中项的索引:var index=myselect.selectedIndex ; // selectedIndex代表的是你所选中项的index 3:拿到选中项options的value: myselect.options[index].value; ...
function debounce(fn, wait) { let start = null; return () => { clearTimeout(start); start = setTimeout(fn, wait); }; } 适用于文本输入的 keydown 和 keyup 两个事件,常应用于文本框自动补全。 节流与防抖最大的不同的地方就是在计算最后执行时间的方式上,著名的开源工具库 underscore 中有...