Example introduction to the difference between id and name attributes in input_HTML/Xhtml_Web page production

I have been building a website for a long time, but I still haven’t figured out the difference between name and id in input. I recently learned jquery and encountered this problem again, so I collected information online. After seeing this article, I sorted it out for later use.

It can be said that almost everyone who has done web development has asked, what is the difference between the ID and Name of an element? Why do we need Name when we have ID?! And we can also get the most classical answer: ID is like a person's ID number, and Name is like his name. ID is obviously unique, and Name is repeatable.

Last week I also encountered the problem of ID and Name. I entered an input type="hidden" on the page and only wrote an ID='SliceInfo'. After assigning the value, submit and use Request in the background. Params["SliceInfo"] cannot get the value. Later, I suddenly realized that it should be marked with Name, so I added Name='SliceInfo' to the input, and everything was ok.

The answer to ID and Name in the first paragraph is too general. Of course, that explanation is completely correct for ID, which is the Identity of the HTML element on the client side. Name is actually much more complicated, because Name has many uses, so it cannot be completely replaced by ID, thus canceling it. Specific uses are:

Use 1: As a server-side indicator of HTML elements that can interact with the server, such as input, select, textarea, and button. We can get the value submitted by the element through Request.Params based on its Name on the server side.
Use 2: HTML element Input type='radio' grouping, we know that the radio button control is in the same grouping class, the check operation is mutex, only one radio can be selected at the same time, this grouping is based on the same Name attribute realized.
Use 3: Establish an anchor point in the page. We know that link is to obtain a page hyperlink. If you do not use the href attribute, use Name instead, such as: < ;a name="PageBottom">, we get a page anchor.
Use 4: Identity as an object, such as Applet, Object, Embed and other elements. For example, in an Applet object instance, we will use its Name to refer to the object.
Purpose 5: When associating between IMG elements and MAP elements, if you want to define the hotspot area of ​​IMG, you need to use its attribute usemap, so usemap="#name" (Name of the associated MAP element).
Use 6: Attributes of certain specific elements, such as attribute, meta and param. For example, define parameters for Object or in Meta.

Obviously these uses cannot be simply replaced by ID, so the difference between ID and Name of HTML elements is not the difference between ID number and name. They have different functions. .

Of course, the Name attribute of the HTML element can also play a role as an ID in the page, because in the DHTML object tree, we can use document.getElementsByName to obtain an object array containing all specified Name elements in the page. . There is another problem with the Name attribute. When we dynamically create an element that can contain the Name attribute, we cannot simply use the assignment element.name = "..." to add its Name. We must use document.createElement( when creating the Element. '') adds the Name attribute to the element. What does this mean? Just look at the example below to understand.