Javascript 错误 - document.getElementsById 不是函数
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Javascript error - document.getElementsById is not a function
提问by Rahul Singh
Since I am calling this code in loop. But following code is giving me error as document.getElementsByIdis not a function. What should I do how can I call doc.getbyid in loop.
因为我在循环中调用此代码。但是下面的代码给了我错误，因为document.getElementsById它不是一个函数。我应该怎么做如何在循环中调用 doc.getbyid。
for (var z=1; z < i; z++){
var textbox = document.getElementsById("a"+z).value;
var textbox2 = document.getElementsById("b").value;
var textbox3 = document.getElementsById("c").value;
alert(textbox);
alert(textbox2);
alert(textbox3);
}
回答by James Allardice
That's because it getElementById(note the lack of the "s" on "Element"). Which makes sense if you think about it, because idvalues have to be unique in a document, so there will be only one "element" that matches, rather than multiple "elements".
那是因为它getElementById（注意“元素”上缺少“s”）。如果您考虑一下，这是有道理的，因为id值在文档中必须是唯一的，因此只有一个“元素”匹配，而不是多个“元素”。
However, there are methods that return multiple elements which do use the plural "elements", such as getElementsByTagName, so you may just be mixing them up.
但是，有些方法会返回使用复数“元素”的多个元素，例如getElementsByTagName，因此您可能只是将它们混在一起。
回答by Merianos Nikos
The function is not getElementsById but getElementById.
该函数不是 getElementsById 而是 getElementById。
There is no plural form on Element
Element 上没有复数形式
回答by Unknown
Actually you need to use as follows:
其实你需要使用如下：
for (var z = 1; z < i; z++) {
var textbox = document.getElementById("a"+z).value;
var textbox2 = document.getElementById("b").value;
var textbox3 = document.getElementById("c").value;
alert(textbox);
alert(textbox2);
alert(textbox3);
}
回答by Dave Newton
The name of the function is getElementById.
该函数的名称是getElementById。
