原文
https://www.jianshu.com/p/b01f32844ac1
大纲
1、单选框多选框实现的商品选择
2、添加下拉框和删除下拉框
3、观察textarea中事件处理器的运行顺序
推荐
1、单选框多选框实现的商品选择
<html>
<head>
<title>Test</title>
<script>
var radCpuSpeedIndex = 0;
function radCPUSpeed_onclick(radIndex) {
var returnValue = true;
if (radIndex == 1) {
returnValue = false;
alert("Sorry that processor speed is currently unavailable");
/**
Next line works around a bug in IE that doesn't cancel
the Default action properly
*/
document.form1.radCPUSpeed[radCpuSpeedIndex].checked = true;
} else {
radCpuSpeedIndex = radIndex;
}
return returnValue;
}
function butCheck_onclick() {
var controlIndex;
var element;
var numberOfControls = document.form1.length;
var compSpec = "Your chosen processor speed is ";
compSpec =
compSpec + document.form1.radCPUSpeed[radCpuSpeedIndex].value;
compSpec =
compSpec + "
With the following additional components
";
for (controlIndex = 0; controlIndex < numberOfControls; controlIndex++) {
element = document.form1[controlIndex];
if (element.type == "checkbox") {
if (element.checked == true) {
compSpec = compSpec + element.value + "
";
}
}
}
alert(compSpec);
}
</script>
</head>
<body>
<form name="form1">
<p>Tick all of the components you want included on your computer </p>
<br>
<br>
<table>
<tr>
<td>DVD-ROM</td>
<td>
<input type="checkbox" name="cnkDVD" value="DVD-ROM">
</td>
</tr>
<tr>
<td>CD-ROM</td>
<td>
<input type="checkbox" name="cnkCD" value="CD-ROM">
</td>
</tr>
<tr>
<td>ZIP-ROM</td>
<td>
<input type="checkbox" name="cnkZIP" value="ZIP DRIVE">
</td>
</tr>
</table>
<p>Select the processor speed you require </p>
<br>
<br>
<table>
<tr>
<td>
<input type="radio" name="radCPUSpeed" checked onclick="return radCPUSpeed_onclick(0)" value="3.8 GHz">
</td>
<td>3.8 GHz</td>
</tr>
<tr>
<td>
<input type="radio" name="radCPUSpeed" checked onclick="return radCPUSpeed_onclick(1)" value="4.8 GHz">
</td>
<td>4.8 GHz</td>
</tr>
<tr>
<td>
<input type="radio" name="radCPUSpeed" checked onclick="return radCPUSpeed_onclick(2)" value="6 GHz">
</td>
<td>6 GHz</td>
</tr>
</table>
<input type="button" value="Check Form" name="butCheck" onclick="return butCheck_onclick()">
</form>
</body>
</html>
2、添加下拉框和删除下拉框
<html>
<head>
<title>Test</title>
<script>
function butRemoveWeb_onclick(){
if(document.form1.theDay.options[2].text == "Wednesday"){
document.form1.theDay.options[2] = null;
}else{
alert("There is no Wednesday here!");
}
console.log(document.form1.theDay.selectedIndex);
}
function butAddWed_onclick(){
if(document.form1.theDay.options[2].text != "Wednesday"){
var indexCounter ;
var days = document.form1.theDay;
var lastoption = new Option();
days.options[6] = lastoption;
for(indexCounter = 6;indexCounter >2; indexCounter--){
days.options[indexCounter].text = days.options[indexCounter -1].text;
days.options[indexCounter].value = days.options[indexCounter -1].value;
}
var option = new Option("Wednesday",2);
days.options[2] = option;
}
else{
alert("Do you want to have TWO Wednesday????");
}
console.log(document.form1.theDay.selectedIndex);
}
</script>
</head>
<body>
<form name="form1">
<select name=theDay size=5>
<option value=0 selected>Monday
<option value=1>Tuesday
<option value=2>Wednesday
<option value=3>Thursday
<option value=4>Friday
<option value=5>Saturday
<option value=6>Sunday
</select>
<br>
<input type="button" value="Remove Wednesday" name=butRemoveWeb onclick="butRemoveWeb_onclick()">
<input type="button" value="Add Wednesday" name=butAddWeb onclick="butAddWed_onclick()">
</form>
</body>
</html>
3、观察textarea中事件处理器的运行顺序
<html>
<head>
<title>Test</title>
<script>
//观察textarea中事件处理器的运行顺序
function DisplayEvent(eventName){
var myMessage = window.document.form1.textarea2.value;
myMessage = myMessage + eventName;
window.document.form1.textarea2.value = myMessage;
}
</script>
</head>
<body>
<form name="form1">
<textarea rows=15 cols=40 name=textarea1
onchange = "DisplayEvent('onchagen
');"
onkeydown = "DisplayEvent('onkeydown
');"
onkeypress = "DisplayEvent('onkeypress
');"
onkeyup = "DisplayEvent('onkeyup
');"
></textarea>
<textarea rows=15 cols=40 name=textarea2></textarea>
<br><br>
<input type="button" value="Clear Event TextArea"
name=button1 onclick="window.document.form1.textarea2.value=''"
>
</form>
</body>
</html>
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