Control Flow in Angular?

Angular · Theory

Control Flow

Theory

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Control Flow

Control Flow is a Angular topic. In plain words you use it for a Pass banner in a marks card. Don’t start with a slogan — start with that picture.

Smallest example: *ngIf="marks >= 40". Type it, run it, and say what you see. If you can do that from memory, you know Control Flow.

From the example next to this theory — Control Flow: toggle open.

Trap — *ngIf treating 0 as false. Fix that before you talk about advanced Angular.

Viva — what is Control Flow? Then show *ngIf="marks >= 40". Then name the trap.

Exam tip

What is Control Flow? Show this: *ngIf="marks >= 40". Trap: *ngIf treating 0 as false.

Example

import { Component } from "@angular/core";

@Component({
  selector: "app-root",
  template: `
    <h1>{{ title }}</h1>
    <button (click)="toggle()">Toggle</button>
    <p *ngIf="open">Panel open</p>
  `,
})
export class AppComponent {
  title = "Angular practice";
  open = true;
  toggle() {
    this.open = !this.open;
  }
}

Control Flow: toggle open. Say whether the panel is on screen after one click.

Short notes

DefControl Flow — a Pass banner in a marks card.
Rule*ngIf="marks >= 40"
Trap*ngIf treating 0 as false
Usea marks card

import { Component } from "@angular/core"; @Component({ selector: "app-root", template: ` <h1>{{ title }}</h1> <button (click)="toggle()">Toggle</button> <p *ngIf="open">Panel open</p> `, }) export class AppComponent { title = "Angular practice"; open = true; toggle() { this.open = !this.open; } }

Control Flow

Example

Short notes

Questions

Control Flow

Code Examples for Control Flow

Control Flow — working example

How to Explain Control Flow to an Interviewer

What is Control Flow?

Give one small example of Control Flow.

What mistake do beginners make with Control Flow?

Where do you use Control Flow?

Control Flow

Example

Short notes

Questions