当/如果输入值实时更改使用jQuery时，如何显示警报？

Question

I am trying to show alert if input value change. I am using jQuery, so here is a demo what i am trying to do but alert not showing / not working. Thanks

 $(".d1, .d2").click( function (e) { var $this = $(this); $(".input").attr('value', $this.text()); }); $(".input").change( function() { alert(this.value); }); 

 .d1, .d2 {cursor:pointer;border:1px solid black;margin-top:10px;padding:5px} 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script> <input class="input" value="" /><p/> <a class="d1">Demo 1</a> <a class="d2">Demo 2</a> 

Answer 1

You need to use .val() method to set value of input element, Since you are using the change event in input on programatically changing the value it will not execute. You need to use .trigger(event)

Execute all handlers and behaviors attached to the matched elements for the given event type.

 $(".d1, .d2").click( function (e) { var $this = $(this); $(".input").val($this.text()).trigger('change'); }); $(".input").change( function() { alert(this.value); }); 

 .d1, .d2 {cursor:pointer;border:1px solid black;margin-top:10px;padding:5px} 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script> <input class="input" value="" /><p/> <a class="d1">Demo 1</a> <a class="d2">Demo 2</a>