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Lifecycle & Projection
Preview — 3 of 10 questions
What is the key difference between constructor and ngOnInit in an Angular component?
AThe constructor runs after change detection; ngOnInit runs before
BngOnInit only runs once; the constructor can run multiple times
CThe constructor is for DI and basic setup; ngOnInit runs after inputs are set and is the right place for initialization logic
DThere is no practical difference — use whichever you prefer
How do you pass data from a parent component to a child component in Angular?
AUsing a shared service with a BehaviorSubject
BDecorating a child property with @Input() and binding to it in the parent's template
CUsing the @Output() decorator on the parent
DAccessing the parent component via ViewChild
How does a child component notify its parent of an event?
ABy directly calling a method on the parent component's instance
BBy decorating a property with @Output() using an EventEmitter and calling .emit()
CBy dispatching a native DOM CustomEvent
DBy modifying a shared object passed via @Input()
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