How to detect value change on hidden input field in JQuery ?
In the <input> element with the type=”hidden”, the change() method of jQuery is not automatically triggered. The change() method is only triggered automatically when the user himself changes the value of the field and not the developer. When the developer changes the value inside the hidden field, he has to trigger the change as well.
There two possible way to detect the value change on the hidden input field:
- By using bind() method
- By using change() method
Below examples will illustrate both the methods to detect the change of value in the hidden field.
Example 1: The following example uses the inbuilt bind() method of jQuery.
<!DOCTYPE html><html> <head> <title> By using bind() method detecting change of value in the hidden field </title> integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU=" crossorigin="anonymous"> </script></head> <body style="text-align:center;"> <h1 style="color:green;"> GeeksforGeeks </h1> <h3>By using bind() method</h3> <form> <input type="hidden" value="" id="hidField"> <button type="button" id="changeValue"> Click to change value </button> </form> <script> $(document).ready(function() { alert("Value of hidden field before updating: " + $("#hidField").val()); $("#changeValue").click(function() { $("#hidField").val(10).trigger("change"); }); $("input[type='hidden']").bind("change", function() { alert("Value of hidden field after updating: " + $(this).val()); }); }) </script></body> </html> |
Output:
Example 2: The following example uses the inbuilt change() method of jQuery.
<!DOCTYPE html><html> <head> <title> By using change() method detecting change of value in the hidden field </title> integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU=" crossorigin="anonymous"></script></head> <body style="text-align:center;"> <h1 style="color:green;"> GeeksforGeeks </h1> <h3>By using change() method</h3> <form> <input type="hidden" value="" id="hidField"> <br> <button type="button" id="changeValue"> Click to change value </button> </form> <script> $(document).ready(function() { alert("Value of hidden field before updating: " + $("#hidField").val()); $("#changeValue").click(function() { $("#hidField").val(101).trigger("change"); }); $("#hidField").change(function() { alert("Value of hidden field after updating: " + $("#hidField").val()); }); }) </script></body> </html> |
Output:
jQuery is an open source JavaScript library that simplifies the interactions between an HTML/CSS document, It is widely famous with it’s philosophy of “Write less, do more”.
You can learn jQuery from the ground up by following this jQuery Tutorial and jQuery Examples.
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