HTML DOM model: Before the w3c dom model (specification) appeared, each browser supported some DOM operations
Select object
Attributes: selectedIndex: indicates the subscript of the option currently selected by the user (from 0 Start) length: Get or set the length of the option options: The value is an array, each array element is an option object, representing all the options of the drop-down list Option object
Attributes: text: Description of the option value: The value of the option selected: When the value is true, it means that this option is selected by the user and the Option object can be created as follows
var obj = new Option(text, value);
<html>
<head>
<script src="myjs.js"></script>
<script>
function f1(){
//alert($('s1').selectedIndex);
//alert($('s1').length);
var arr = $('s1').options;
for(i=0;i<arr.length;i++){
alert(arr[i].text +' '+ arr[i].value);
}
}
function f2(){
var op = new Option('武汉','wh');
$('s1').options[$('s1').options.length] = op;
}
</script>
</head>
<body>
<select id="s1" style="width:120px;" name="s1">
<option value="bj">北京</option>
<option value="sh">上海</option>
<option value="xa">西安</option>
<option value="sz">深圳</option>
<option value="tj">天津</option>
</select>
<input type="button" value="点我吧" onclick="f2();"/>
</body>
</html>Cascading drop-down list
<html>
<head>
<script src="myjs.js"></script>
<script>
var arr = new Array();
arr[0] = [new Option('--方向--','-1')];
arr[1] = [new Option('商务英语','en1'),
new Option('专业英语','en2')];
arr[2] = [new Option('计算机软件','comp1'),
new Option('计算机网络','comp2'),
new Option('计算机应用','comp3')];
//数组的创建放在外面执行效率更高
function change(index){
$('s2').length = 0;
for(i=0;i<arr[index].length;i++){
$('s2').options[i] = arr[index][i];
}
}
</script>
</head>
<body>
<select id="s1" style="width:120px;" onchange="change(this.selectedIndex);">
<!-- this表示绑定该事件的节点,在这里表示<select>节点-->
<option value="-1">--专业--</option>
<option value="english">英语</option>
<option value="computer">计算机</option>
</select>
<select id="s2" style="width:120px;">
<option value="-1">--方向--</option>
</select>
</body>
</html>Table object is equivalent to
<html>
<head>
<script src="myjs.js"></script>
<script>
//html dom模型做
function addRow1(){
var tr = $('t1').insertRow($('t1').rows.length);
var td1 = tr.insertCell(tr.cells.length);
var td2 = tr.insertCell(tr.cells.length);
td1.innerHTML = $('name').value;
td2.innerHTML = $('salary').value;
//tr.style.backgroundColor = 'red'; //两种样式1
//tr.className = 'selected'; //两种样式2
$('t1').rows[1].cells[1].style.backgroundColor = 'red';//把某一格加亮
}
//采用w3c dom模型做
function addRow2(){
var tr1 = document.createElement('tr');
var td1 = document.createElement('td');
var td2 = document.createElement('td');
td1.innerHTML = $('name').value;
td2.innerHTML = $('salary').value;
tr1.appendChild(td1);
tr1.appendChild(td2);
$('t1').appendChild(tr1);
}
</script>
<style>
.selected{
background-color:red;
}
</style>
</head>
<body>
<table id="t1" border="1" cellpadding="0" cellspacing="0" width="60%">
<tr><td>姓名</td><td>工资</td></tr>
<tr><td>zs</td><td>2000</td></tr>
<tr><td>ls</td><td>3000</td></tr>
<tr><td>wu</td><td>4000</td></tr>
</table><br/>
姓名：<input type="text" name="name" id="name"/>
工资：<input type="text" name="salary" id="salary"/>
<input type="button" value="添加" onclick="addRow2();"/>
</body>
</html>The above is the content of Xiaoqiang’s HTML5 mobile development road (31) - JavaScript review 6. For more related content, please pay attention to the PHP Chinese website (www.php.cn)! |
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