Creating a service with CLI in Angular - Practice Exercises

Challenge - 5 Problems

📝 Syntax

intermediate

What is the correct Angular CLI command to create a service named user?

Choose the exact Angular CLI command that generates a service named user in the default folder.

A ng create service user

B ng generate service user

C ng new service user

D ng make service user

💡 Hint

The Angular CLI uses generate or its shorthand g to create new files.

The correct command to create a service is ng generate service user. The other commands are invalid Angular CLI commands.

❓ component_behavior

intermediate

What will be the providedIn scope of a service created with ng generate service user by default?

After running ng generate service user, what is the default providedIn value in the generated service's decorator?

A providedIn: 'platform'

B No providedIn property is set by default

C providedIn: 'any'

D providedIn: 'root'

💡 Hint

Angular services are usually provided at the root level for app-wide singleton behavior.

By default, Angular CLI adds providedIn: 'root' to the service decorator. This makes the service available app-wide as a singleton.

🔧 Debug

advanced

Why does this Angular CLI command fail? ng generate service

You run ng generate service without any name. What error will Angular CLI show?

A Error: Service already exists

B No error, service created with default name

C Error: Missing required argument: name

D Error: Invalid command syntax

💡 Hint

The CLI needs a name to create a service file.

The Angular CLI requires a service name argument. Running ng generate service alone causes an error about missing the required name argument.

❓ state_output

advanced

What files are created by ng generate service auth?

Select the exact files generated by Angular CLI when creating a service named auth.

A auth.service.ts and auth.service.spec.ts

B auth.service.ts only

C auth.ts and auth.spec.ts

D auth.service.ts, auth.service.spec.ts, and auth.module.ts

💡 Hint

Angular CLI generates a TypeScript file and a test spec file for services.

By default, Angular CLI creates two files: auth.service.ts and auth.service.spec.ts for the service and its tests.

🧠 Conceptual

expert

Which Angular CLI command creates a service in a specific folder shared with the name logger?

You want to create a service named logger inside the src/app/shared folder using Angular CLI. Which command is correct?

A ng generate service shared/logger

B ng generate service logger/shared

C ng generate service logger --folder=shared

D ng generate service --path=shared logger

💡 Hint

Use the folder path before the service name separated by a slash.

The correct syntax is ng generate service shared/logger. The CLI interprets the path before the slash as the folder and the last part as the service name.