You need to use named functions. Also, the click variable needs to be outside the handler to increment. var click_count = 0; function myClick(event) { click_count++; if(click_count == 50) { // to remove canvas.removeEventListener(‘click’, myClick); } } // to add canvas.addEventListener(‘click’, myClick); EDIT: You could close around the click_counter variable like this: var myClick = … Read more
One big argument against inline event handlers, and the argument that is addressed by the other answers here is the separation of presentation and logic. However, there is actually a bigger problem IMO: The somehow elusive way how inline event handlers are evaluated. As you may know, the content of the on* attributes will be … Read more
Reason is setState is asynchronous, you can’t expect the updated state value just after the setState, if you want to check the value use a callback method. Pass a method as callback that will be get executed after the setState complete its task. Why setState is asynchronous ? This is because setState alters the state … Read more
When do they fire? window.onload By default, it is fired when the entire page loads, including its content (images, CSS, scripts, etc.). In some browsers it now takes over the role of document.onload and fires when the DOM is ready as well. document.onload It is called when the DOM is ready which can be prior … Read more
As noted in comments, some of this becomes irrelevant in Java 8, where final can be implicit. Only an effectively final variable can be used in an anonymous inner class or lambda expression though. It’s basically due to the way Java manages closures. When you create an instance of an anonymous inner class, any variables … Read more
DOM event delegation is a mechanism of responding to ui-events via a single common parent rather than each child, through the magic of event “bubbling” (aka event propagation). When an event is triggered on an element, the following occurs: The event is dispatched to its target EventTarget and any event listeners found there are triggered. … Read more
return false from within a jQuery event handler is effectively the same as calling both e.preventDefault and e.stopPropagation on the passed jQuery.Event object. e.preventDefault() will prevent the default event from occuring, e.stopPropagation() will prevent the event from bubbling up and return false will do both. Note that this behaviour differs from normal (non-jQuery) event handlers, … Read more