Question

php文件：

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script type="text/javascript">

$('.mark').change(function(){
    var data= $(this).val();
    alert(data);
});
</script>

</head>
<body >

<select class='mark' required>
<option value='' disabled selected>Marketplace </option>
<option value='Amazon' >Amazon</option>
<option value='Flipkart' >Flipkart</option>
</select>

</body>
</html>

我想在选择选项时更改输入文本字段的占位符。但要首先应该调用jquery但是上面的代码不能正常工作请告诉我一些事情。我想在选择选项时更改输入文本字段的占位符。但要首先应该调用jquery但是上面的代码不起作用请告诉我一些事情。

Answer 1

您可能忘了添加jQuery库，可以查看以下代码段

$('.mark').change(function(){
	var data= $(this).val();
	alert(data);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select class='mark' required>
	<option value='' disabled selected>Marketplace </option>
	<option value='Amazon' >Amazon</option>
	<option value='Flipkart' >Flipkart</option>
</select>

Answer 2

工作正常，请点击此处。我想你忘了在你的代码中添加jquery库。

$('.mark').change(function(){
   var data= $(this).val();
   alert(data);
 });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>


<select class='mark' required>
  <option value='' disabled selected>Marketplace </option>
  <option value='Amazon' >Amazon</option>
  <option value='Flipkart' >Flipkart</option>
</select>

Answer 3

检查这个完美的工作！

＆＃13;

 $('.mark').change(function(){
   var data= $(this).val();
   alert(data);
 });

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<select class='mark' required>
  <option value='' disabled selected>Marketplace </option>
  <option value='Amazon' >Amazon</option>
  <option value='Flipkart' >Flipkart</option>
</select>

＆＃13;

Answer 4

请试试这个：

$(document).on("change",".mark",function(){
   var data= $(this).val();
   alert(data);
 });

Answer 5

理想情况下你应该这样做： HTML代码：

$(document).ready(function() {

    $('#mark1').change(function() {
    
      alert($(this).val());
    });
  })

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<html>

<body>

  <select class='mark' required id='mark1'>
        <option value='' disabled selected>Marketplace </option>
        <option value='Amazon' >Amazon</option>
        <option value='Flipkart' >Flipkart</option>
    </select>

</body>

</html>

Answer 6

Use jQuery plugin

<select class='mark' required>
  <option value='' disabled selected>Marketplace </option>
  <option value='Amazon' >Amazon</option>
  <option value='Flipkart' >Flipkart</option>
</select>

Answer is
$(document).ready(function() {
    $(".mark").on("change",function(){
        var selected_value = $(this).val();  //get option tag value
        var selected_text = $(this).find(":selected").text(); // get option tag text
        alert(selected_value+" == "+selected_text); //print the result
    });
});

jquery没有选择更改事件

6 个答案: