已选择选项时触发功能

Question

I want to call a function when already selected OPTION is select from drop-down.

 $("#dropdown1").on("change",function(){ alert($(this).val()); }); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <select id="dropdown1"> <option value="one"> One </option> <option value="two"> Two </option> <option value="three"> Three </option> </select> 

In above code, when i select option ONE than ALERT works. So, now option ONE is selected. But i want that when i select option ONE again, than function should call again.

Answer 1

Your event is change, if you select the same value again then there is no change, so no alert is fired.Introduce a dummy option which is hidden. Make all the calculations/manipulation you want to do with the selected value and then change the value to the dummy option element

 $("#dropdown1").on("change",function(){ alert($(this).val()); $(this).val(""); }); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <select id="dropdown1"> <option value="" disabled style="display:none;">Select</option> <option value="one" selected> One </option> <option value="two"> Two </option> <option value="three"> Three </option> </select>