Example tutorial on using html form tags to interact with users

Use form tags to interact with users

How does the website interact with users? The answer is to use HTML form(form). The form can transmit the data entered by the viewer to the server, so that the server-side program can process the data passed by the form.

Grammar:

<form   method="传送方式"   action="服务器文件">

Explanation:

1.ff9c23ada1bcecdd1a0fb5d5a0f18437: ff9c23ada1bcecdd1a0fb5d5a0f18437 tags are in pairs Appears, starting with ff9c23ada1bcecdd1a0fb5d5a0f18437 and ending with f5a47148e367a6035fd7a2faa965022e.

2.action :The place where the data entered by the visitor is sent, such as a PHP page (save.php).

3.method ： Method of data transmission (get/post).

<form    method="post"   action="save.php">
        <label for="username">用户名:</label>
        <input type="text" name="username" />
        <label for="pass">密码:</label>
        <input type="password" name="pass" />
</form>

Note:

1. All form controls (text box, text field, button, Radio button, checkbox, etc.) must be placed between the ff9c23ada1bcecdd1a0fb5d5a0f18437f5a47148e367a6035fd7a2faa965022e tags (otherwise the information entered by the user may not be submitted to the server!).

The get and post methods in Form correspond to the GET and POST methods respectively during the data transmission process.
The main differences between the two are as follows:

1. Get adds the data in the form to the end of the URL pointed to by the action in the form of variable=value, and the two are connected using "?", and each Variables are connected using "&"; Post puts the data in the form in the data body of the form, and passes it to the URL pointed to by the action according to the corresponding method of variables and values.
The following form:

php.cn/test.
asp
?name=lilian&password=12345678

2. Get is not safe, because during the transmission process, the data is stored in the requested URL address, so there may be Some private information is seen by third parties.
3. The amount of data transmitted by the Get method is very small, generally limited to about 2KB, but the execution efficiency is better than the Post method; while the amount of data transmitted by the Post method is relatively large, it is waiting for the server to read the data, but There is also a byte limit. This is to avoid malicious attacks on the server with large amounts of data. According to Microsoft, Microsoft has a limit on the maximum data that can be received using Request.Form(). It is 80KB bytes in IIS4 and 80KB in IIS5. 100KB bytes.

To sum up, please try to use the Post method.

【Related recommendations】

1. Free html online video tutorial

2. html development manual

3. php.cn original html5 video tutorial

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