March 07, 2019
Today I learned about DOM manipulation via JS and the different cases of the
You can get/set classes of elements with
When you add an event listener to an element, an event object is passed to the callback function. The event object has many useful properties on it such as:
.targetwhich shows you which element triggered the event
.parentNodewhich shows you the parent element of the target
parseInt() is a built in method which converts numerical strings into numbers
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) (E.g. adding an event listener to a
<ul> element rather than adding one to each child
this keyword can be thought of as a special variable that changes depending on the situation.
Case 1: In a regular function, (or if you're not in a function at all)
this points to the
Case 2: When a function is called as a method,
this points to the object that's on the left side of the dot
Case 3: In a function that's being called as a constructor,
thispoints to the object that the constructor is creating.
Case 4: When you explicitly set the value of
this manually using
.call, it's all up to you. (.bind, .apply. and .call are methods on functions where
this is set to the first argument passed).
this keyword information so it was a great refresher. Looking forward to the premium material!
P.S. Also applied to Lambda School. Will do my best to get accepted!