title: How to create optional router argument in angular 7
body: <p>I am have a router configuration shown below.</p>
  
  <pre><code>const routes: Routes = [
    {
      path: 'Registration',
      component: RegisterComponent,
      children: [
        { path:'',component:ProfileComponent},
        { path: 'Dependent', component: DependentComponent },
        { path: 'Matrimony', component: MatrimonyComponent },
        { path: 'Subscription', component: MagazinesubscriptionComponent },
        { path: 'Donation', component: DonationComponent }
          ]
    },
    {
      path: 'Profile',
       component: ProfilelistComponent
      //component: VoteprofileComponent
    }
  ];
  </code></pre>
  
  <p>This same router i want to use for editing. Mean like shown below. </p>
  
  <pre><code>const routes: Routes = [
    {
      path: 'Registration/:id',
      component: RegisterComponent,
      children: [
        { path:'',component:ProfileComponent},
        { path: 'Dependent', component: DependentComponent },
        { path: 'Matrimony', component: MatrimonyComponent },
        { path: 'Subscription', component: MagazinesubscriptionComponent },
        { path: 'Donation', component: DonationComponent }
          ]
    },
    {
      path: 'Profile',
       component: ProfilelistComponent
      //component: VoteprofileComponent
    }
  ];
  </code></pre>
  
  <p>Is there anyway in angular without replicating the complete route config I can achieve.</p>
  
  <p>Mean i can specify the parameter as optional?</p>