Angular v21 improves forms handling and dependency injection for better scalability and cleaner code.

#Reactive Forms

import { FormControl, FormGroup } from '@angular/forms';

const loginForm = new FormGroup({
  username: new FormControl(''),
  password: new FormControl(''),
});

Listen to value changes:

loginForm.valueChanges.subscribe((value) => console.log(value));

#Optional Injectors

import { inject, Optional } from '@angular/core';

const myService = inject(MyService, { optional: true });

#Dependency Injection Tokens

bootstrapApplication(AppComponent, {
  providers: [{ provide: API_URL, useValue: 'https://api.example.com' }],
});

#Forms + Signals

const username = signal('');
const password = signal('');

function login() {
  console.log(username(), password());
}

#Conclusion

Angular v21 streamlines reactive forms and dependency injection, making apps more maintainable, scalable, and type-safe.