Q: afterRender vs afterNextRender vs ngAfterViewInit — which to use?

**Target Audience:** Developers who have used ngAfterViewInit to touch the DOM and want to know when the newer render hooks are the better choice, especially in apps with server-side rendering. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The "Verified" blocks were compiled with ngc on Angular 22.2.3 and run in jsdom; the server-side results came from @angular/platform-server

Q: output() vs @Output() EventEmitter — the new signal outputs?

**Target Audience:** Developers who know @Output() and EventEmitter — assumes the basics of [child-to-parent events](/interview-question/how-do-child-components-emit-events-to-parents). **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The basics of emitting an event are covered in [how child components emit events to parents](/interview-question/how-do-child-components-emit-events-to-parents); this

Question 1

What is the difference between the constructor and ngOnInit?

Accepted Answer

**Target Audience:** Anyone preparing for an Angular interview who knows what a component and an input are. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The call order, the NG0950 runtime error and the NG8118 compiler error below were all produced by compiling and running the example on Angular 22.2.3. ## 1. Why This Even Matters — A Story First Think of a new employee's first day. Before they arrive, HR builds their des

Question 2

What is the purpose of ngOnChanges and how does it capture changes in @Input properties?

Accepted Answer

**Target Audience:** Developers preparing for an Angular interview who have written a component with an @Input and want to know exactly when Angular tells the component that the input changed. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary an interviewer expects. Everything under a "Verified" heading was compiled with ngc (strict templates) on Angular 22.2.3 and run; the output

Question 3

Explain what output() and outputFromObservable() are in modern Angular and how they differ from @Output().

Accepted Answer

**Target Audience:** Developers comfortable with RxJS basics who want to expose streams as component outputs. **Difficulty:** Medium to Hard > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The plain comparison of output() with EventEmitter is in [output() versus @Output()](/interview-question/output-vs-output-eventemitter-the-new-signal-outputs); this doc focuses on the RxJS interop functions. Outputs were produced by co

Question 4

What are Angular lifecycle hooks?

Accepted Answer

**Target Audience:** Developers preparing for an Angular interview who know what a component is and want the hook order down cold, including how a parent and its child interleave. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every ordering claim below comes from a parent and child that log each hook, compiled with ngc on Angular 22.2.3 and run; the numbered lists are the real output. ## 1. Why This

Question 5

afterRender vs afterNextRender vs ngAfterViewInit — which to use?

Accepted Answer

**Target Audience:** Developers who have used ngAfterViewInit to touch the DOM and want to know when the newer render hooks are the better choice, especially in apps with server-side rendering. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The "Verified" blocks were compiled with ngc on Angular 22.2.3 and run in jsdom; the server-side results came from @angular/platform-server

Question 6

output() vs @Output() EventEmitter — the new signal outputs?

Accepted Answer

**Target Audience:** Developers who know @Output() and EventEmitter — assumes the basics of [child-to-parent events](/interview-question/how-do-child-components-emit-events-to-parents). **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The basics of emitting an event are covered in [how child components emit events to parents](/interview-question/how-do-child-components-emit-events-to-parents); this

Question 7

What is the difference between afterRender and afterNextRender lifecycle hooks?

Accepted Answer

**Target Audience:** Developers who know that one render hook runs once and the other repeatedly, and want the mechanics an interviewer probes next: phases, pipelining, and what "every render" really means. **Difficulty:** Medium to Hard > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Phase names and guarantees are quoted from the installed Angular 22.2.3 typings; every ordering claim was produced by the runnable example below, compiled with

Question 8

How do you implement custom routing strategies by extending RouteReuseStrategy?

Accepted Answer

**Target Audience:** Developers comfortable with routing who need finer control over component lifetimes — assumes you know [routing basics](/interview-question/how-does-routing-and-lazy-loading-work-in-angular) and [lifecycle hooks](/interview-question/what-are-angular-lifecycle-hooks). **Difficulty:** Hard > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every constructor, destroy, store and outlet-event line in sections 5 and 6 was printed by t

ANGULARDECODED.

Easy