Form structure and form object study notes

1. The form on the webpage (Form) is used to fill in information for the visitors, so as to obtain user information, so that the webpage has interactive functions. The form has two important components: one is the HTML source code that describes the form; the other is the server-side application or client-side script used to process the user input information in the form field, such as Asp, net, JSP, JavaScript, etc.
2. Basic syntax:

<form name="..." action="..." method="...">
<input>
...
<slect>...</select>
...
<textarea>...</textarea>
</form>

1. Single line text input box
Basic syntax:

<input name="text" type="text" maxlength=" " size=" " value=" ">

• When type == "text", it means that the input information of the input item is a character string.
  
  
  2. Submit button and reset button
  Basic syntax: <input name="submit" type="submit" value="提交">
  Submit button: <input name="submit" type="submit" value="重置">
  
  3. Password input box
  Basic syntax:

<input name="password" type="password" maxlength=" " size=" " value=" ">

• maxlength indicates the maximum characters that can be entered in the input box.
• size indicates the number selected in the list.
  
  
  4. Checkbox
  Basic syntax:

<input name="checkbox" type="checkbox" value=" ">

• There are multiple options in the checkbox, so name should be multiple.
• The value of value should be the same.
  
  
  5. Radio button
  Basic syntax:

<input name="checkbox" type="checkbox" value=" " >

• Only one radio button can be selected, so the value of name should be the same.
• The value of value should be different.
  
  
  6. Image button
  Basic syntax:

<input name="image" type="image" src=" ">

• image means to create an image control, click on the control image will be submitted.
• src indicates the path used to set the image.
  
  
  7. Multi-line text input box
  Basic syntax:

<textarea name="textarea" cols=" " rows=" " wrap=" "></textarea>

• <textarea>It is a double label and should be used in the form label.
• rows represents the number of rows entered in a multi-line text box.
• cols represents the number of columns entered in the multi-line text box.
• Wrap means that the default text wraps automatically.
  
  
  8. Drop-down list box
  Basic syntax:

<select name=" ">
   <option value=" ">
   ...
 </select>

9. Multi-select drop-down list box
Basic syntax:

<select name=" " size=“ ” multiple=" ">
    <option value=" ">
    ...
</select>

• Multipe means that the user is allowed to select multiple items from the list.
  
  
  Knowledge summary:
  table structure: <form>...</form>
  input: <input>nine types of single mark and type.
  Multi-line text box: <textarea>...</testarea>
  drop-down list box:<select><option>...<select></option>