HTML必填项如何设置?
 
 
 
  HTML必需属性是一个布尔属性,它指定必须在提交表单之前填写输入元素。此属性与以下元素一起使用:
 
<input> 
<select> 
<textarea> 
<input>
 
 我们可以轻松地将必需属性与<input>元素一起使用,如以下语法所示:
 
 
 
 示例 
 
 
  
   <html>
 <head>
 <title>
 Example of required attribute with input element 
 </title>
 <style>
 div
 {
 padding: 10px 0;
 }
 </style>
 <head>
 <body>
 <form>
 <div>
 <label>Name</label> 
 <input type="text" placeholder="Enter Name" name="name" required> 
 </div>
 <div> 
 <label> E-mail </label> 
 <input type="email" placeholder="Enter email ID" name="email" required> 
 </div>
 <div>
  <label> Mobile No. </label> 
 <input type="text" placeholder="Enter Your Mobile No." name="mobileno" required>
 </div>
 <div>
 <label>Password</label> 
 <input type="password" placeholder="Enter Password" name="psw" required> 
 <br>
   </div> 
 <button type="submit" VALUE="SUBMIT"> SUBMIT </button>
 </form>
 </body>
 </html>
  
 
 
  
 
 输出: 
 
 
 <select> 
 
 我们可以轻松地将必需属性与
 <select>元素一起使用,如以下语法所示:
 
 
 
 示例 
 
 
  
   <html>
 <head>
 <title> Example of required attribute with select option </title>
 <style>
 div
 {
 padding: 10px 0;
 }
 </style>
 <head>
 <body>
 <form>
 <label> 
 Course :
 </label> 
 <select required>
 <option value="">None</option>
 <option value="BCA">BCA</option>
 <option value="BBA">BBA</option>
 <option value="B.Tech">B.Tech</option>
 <option value="MBA">MBA</option>
 <option value="MCA">MCA</option>
 <option value="M.Tech">M.Tech</option>
 </select>
 <button type="submit" VALUE="SUBMIT"> SUBMIT </button>
 </form>
 </body>
 </html>
  
 
 
  
 
 输出: 
 
 
 <textarea> 
 
 我们还可以轻松地将必需属性与
  <textarea> 元素一起使用,如以下语法所示:
 
 
 
 示例 
 
 
  
   <html>
 <head>
 <title> Example of required attribute with textarea </title>
 <style>
 div
 {
 padding: 10px 0;
 }
 </style>
 <head>
 <body>
 <form>
 Any Comment :
 <br>
 <textarea cols="80" rows="5" placeholder="Enter a comment" value="address" required>
 </textarea>
 <button type="submit" VALUE="SUBMIT"> SUBMIT </button>
 </form>
 </body>
 </html>
  
 
 
  
 
 输出: 
 
 
浏览器支持