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How to Correctly Implement a Click Event Listener on a JavaScript Class?
How to Correctly Implement a Click Event Listener on a JavaScript Class?
Dec 02, 2024 pm 12:31 PM
Implementing a Click Event Listener on a Class in JavaScript
In JavaScript, event listeners are the preferred method for handling user interactions. When trying to obtain an attribute from a clicked element, listeners provide a more efficient approach than using traditional event handlers.
In the code snippet provided:
var classname = document.getElementsByClassName("classname");
var myFunction = function() {
var attribute = this.getAttribute("data-myattribute");
alert(attribute);
};
classname.addEventListener('click', myFunction(), false);
The issue lies in how addEventListener is invoked. The event listener function myFunction is immediately executed by adding the parentheses after it (myFunction()). Instead, the function reference itself should be passed as the second argument.
classname.addEventListener('click', myFunction, false);
Additionally, getElementsByClassName returns a node list, not an HTML element. To apply the event listener to each element in the node list, it should be iterated over:
var elements = document.getElementsByClassName("classname");
for (var i = 0; i < elements.length; i++) {
elements[i].addEventListener('click', myFunction);
}
In browsers with ES6 support, a more concise solution can be achieved using the forEach method:
Array.from(elements).forEach(function(element) {
element.addEventListener('click', myFunction);
});
By addressing these adjustments, the code should now correctly capture the attribute of the clicked element using a JavaScript event listener without resorting to external libraries like jQuery.
The above is the detailed content of How to Correctly Implement a Click Event Listener on a JavaScript Class?. For more information, please follow other related articles on the PHP Chinese website!
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