How do you define a route parameter in Angular routing?

Question

Admin · Accepted Answer

{ path: 'user/:id', component: UserComponent }

Admin · Answer

{ path: 'user:id', component: UserComponent }

Admin · Answer

{ path: 'user/id', component: UserComponent }

Admin · Answer

{ path: 'user?=id', component: UserComponent }

Q. How do you define a route parameter in Angular routing?