JavaScript 參考手冊(cè)
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HTML DOM Anchor 對(duì)象
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HTML DOM Area 對(duì)象
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HTML DOM Audio 對(duì)象
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HTML DOM Base 對(duì)象
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HTML DOM Blockquote 對(duì)象
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HTML DOM Body 對(duì)象
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HTML DOM Button 對(duì)象
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HTML DOM Canvas 對(duì)象
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HTML DOM Column 對(duì)象
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HTML DOM Columngroup 對(duì)象
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HTML DOM Datalist 對(duì)象
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HTML DOM Dialog 對(duì)象
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HTML DOM Form 對(duì)象
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HTML DOM Frame 和 IFrame 對(duì)象
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HTML DOM Frameset 對(duì)象
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HTML DOM Image 對(duì)象
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HTML DOM ins 對(duì)象
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HTML DOM Button 對(duì)象
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HTML DOM Checkbox 對(duì)象
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HTML DOM Input Color 對(duì)象
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HTML DOM Input Date 對(duì)象
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HTML DOM Input Datetime 對(duì)象
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HTML DOM Input DatetimeLocal 對(duì)象
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HTML DOM Input Email 對(duì)象
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HTML DOM FileUpload 對(duì)象
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HTML DOM Hidden 對(duì)象
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HTML DOM Input Image 對(duì)象
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HTML DOM Input Month 對(duì)象
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HTML DOM Input Number 對(duì)象
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HTML DOM Input Range 對(duì)象
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HTML DOM Password 對(duì)象
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HTML DOM Radio 對(duì)象
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HTML DOM Reset 對(duì)象
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HTML DOM Input Search 對(duì)象
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HTML DOM Submit 對(duì)象
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HTML DOM Input Text 對(duì)象
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HTML DOM Input Time 對(duì)象
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HTML DOM Input URL 對(duì)象
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HTML DOM Input Week 對(duì)象
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HTML DOM Keygen 對(duì)象
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HTML DOM Link 對(duì)象
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HTML DOM Label 對(duì)象
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HTML DOM Legend 對(duì)象
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HTML DOM Li 對(duì)象
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HTML DOM Map 對(duì)象
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HTML DOM Menu 對(duì)象
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HTML DOM MenuItem 對(duì)象
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HTML DOM Meta 對(duì)象
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HTML DOM Meter 對(duì)象
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HTML DOM Object 對(duì)象
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HTML DOM Ol 對(duì)象
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HTML DOM OptionGroup 對(duì)象
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HTML DOM Option 對(duì)象
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HTML DOM Parameter 對(duì)象
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HTML DOM Progress 對(duì)象
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HTML DOM Select 對(duì)象
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HTML DOM Source 對(duì)象
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HTML DOM Style 對(duì)象
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HTML DOM Table 對(duì)象
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HTML DOM td/th 對(duì)象
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HTML DOM TableHeader 對(duì)象
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HTML DOM tr 對(duì)象
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HTML DOM Textarea 對(duì)象
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HTML DOM Title 對(duì)象
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HTML DOM Time 對(duì)象
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HTML DOM Track 對(duì)象
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HTML DOM Video 對(duì)象
Form length 屬性
Form 對(duì)象定義和用法
length 屬性可返回表單中元素的數(shù)目。
語(yǔ)法
formObject.length
瀏覽器支持
所有主要瀏覽器都支持 length 屬性
實(shí)例
實(shí)例
下面的例子可返回表單中元素的數(shù)目：
<html>
<body>
<form id="frm1" action="form_action.html">
First name: <input type="text" name="fname" value="Donald"><br>
Last name: <input type="text" name="lname" value="Duck"><br>
<input type="submit" value="Submit">
</form>
<script>
document.write(document.getElementById("frm1").length);
</script>
</body>
</html>
<body>
<form id="frm1" action="form_action.html">
First name: <input type="text" name="fname" value="Donald"><br>
Last name: <input type="text" name="lname" value="Duck"><br>
<input type="submit" value="Submit">
</form>
<script>
document.write(document.getElementById("frm1").length);
</script>
</body>
</html>
以上實(shí)例輸出結(jié)果：
3
運(yùn)行代碼 ?
更多實(shí)例
Form 對(duì)象其他擴(kuò)展