typescript switch

let day : number = 4;

switch (day) {
    case 0:
        console.log("It is a Sunday.");
        break;
    case 1:
        console.log("It is a Monday.");
        break;
    case 2:
        console.log("It is a Tuesday.");
        break;
    case 3:
        console.log("It is a Wednesday.");
        break;
    case 4:
        console.log("It is a Thursday.");
        break;
    case 5:
        console.log("It is a Friday.");
        break;
    case 6:
        console.log("It is a Saturday.");
        break;
    default:
        console.log("No such day exists!");
        break;
}

switch(expression) { 
   case constant-expression1: { 
      //statements; 
      break; 
   } 
   case constant_expression2: { 
      //statements; 
      break; 
   } 
   default: { 
      //statements; 
      break; 
   } 
}