Null guarding in Angular

In JavaScript, the undefined and null values are a persistent issue that must be proactively dealt with every step of the way. There are multiple ways to guard against null values in Angular:

1. Property Initialization
2. Safe Navigation Operator ?.
3. Null Guarding with *ngIf

Property initialization

In statically-typed languages such as Java, it is drilled into you that proper variable initialization/instantiation is the key to error free operation. So let's try that in CurrentWeatherComponent by initializing current with default values:

src/app/current-weather/current-weather.component.ts
constructor(private weatherService: WeatherService) {
  this.current = {
    city: '',
    country: &apos...