Component lifecycle methods

When a component tag appears, Angular 2 creates an instance of a component, renders it, checks for changes in attributes, checks for changes in state, and destroys it when it's no longer needed. These steps together form the lifecycle of a component.

Angular 2 lets us register methods that are called at various stages of the component lifecycle.

Here are the various lifecycle methods provided by Angular 2; lifecycle hooks are explained in the order they occur:

• ngOnChanges: This is invoked whenever the attributes of a component change. It's also invoked after the attributes of a component are resolved for the first time after the creation of a new instance of the component. It's invoked after the state has been changed due to the attributes but before the view is updated. This method receives the current and previous values of the attributes.

• ngOnInit: This is invoked after the first instance of ngOnChanges. It states that the component has been successfully created...