Detailed introduction to input tags and form tags in html

input tag

The input tag is closed by itself

<input />

The input series includes checkbox, redio, password, button, file, etc.

1, type='text' and type='password'

<input type=&#39;text&#39; />

type='text' and type='password'

用户名：<input type="text"/>
<br/><br/>
密  码：<input type="password"/>

Limit input length: type='text' maxlength ="3"

2. Check box: type='checkbox'

兴趣爱好：
篮球: <input type="checkbox"/>
足球: <input type="checkbox"/>
排球: <input type="checkbox"/>

3. Radio selection Button type='radio'

性别：
男： <input type="radio" name="gender"/> 女：<input type="radio" name="gender"/>

4. Submit button: type='button'

button-normal button, submit-submit button; submit button Generally, information needs to be submitted to the server before it appears on a web page. The button button is to create a button. It is not certain what will happen when the button is implemented. It depends on the page editor to decide. For example, on the same day on the web form, the user inputs There may be input errors or deviations, you can create a button-clear (reset) button on the web page. A form can have multiple ordinary buttons, and at least one submit button (the form web page needs to be submitted)

<input type="button" value="提交"/>

5. Submit button: type='submit'

6. Upload file: type='file'

<input type="file" />

7. Multi-line output box:

<textarea>这里可以输入多行信息</textarea>

form tag:

When the value of Method is get, the content is transmitted through the URL and parameters. At this time, we can see the filled-in content and submission processing through the URL.

When the value of Method is post, the filled-in content and parameters are passed through a similar cache, but the URL cannot see the filled-in content and submission of the form. content.

For the html form form tag, only with the form form and submission method (get post) (understand the difference between get post) can the data be transmitted to the program for processing, otherwise the program cannot receive the data to be processed.

The difference between button and submit:

The button in the form will not submit the data in the form (unless customized, such as customized with JS), while submit will definitely submit the data.

姓名：<input type="text" maxlength="10"/>
密码：<input type="password" />
<br/><br/>
<input type="submit" onclick="alert(123)" value="提交" />

Since submit can submit data, why do we need a button?

The method corresponding to submit is post, which is to submit data to the background, and the method corresponding to button is get. For example, adding a button to the page and setting the value to refresh, then the meaning of the button is to refresh the page. without submitting any data to the background.

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