Why Does My jQuery ID Selector Only Work on the First Element?

jQuery ID Selector Only Selects the First Element: Understanding the Issue

Despite having three buttons with identical IDs, jQuery's #id selector only responds to the first button click. This behavior stems from a fundamental HTML rule dictating that each element must have a unique ID within a document.

Invalid HTML Structure

The HTML code provided violates this rule by assigning the same ID ("xyz") to multiple buttons. According to the HTML specification, "This attribute assigns a name to an element. This name must be unique in a document."

Solution: Convert to Classes

To address this issue, replace the ID attribute with a class attribute for each button:

<button type="button" class="btn btn-primary xyz" value="1">XYZ1</button>
<button type="button" class="btn btn-primary xyz" value="2">XYZ2</button>
<button type="button" class="btn btn-primary xyz" value="3">XYZ3</button>

Revised jQuery Code

With the updated HTML structure, the jQuery code should be modified as follows:

$(".xyz").click(function(){
    alert(this.value);
    // No need for jQuery $(this).val() to get the value of the input.
});

Understanding jQuery's Behavior

jQuery's #id selector only selects the first element with the specified ID in the DOM. This is because the underlying document.getElementById function in the browser performs this behavior.

Conclusion

By following these guidelines, you can effectively handle multiple elements with the same functional purpose in jQuery, ensuring that all buttons respond to clicks as expected.

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