how to explain switch function in javascript code example

Example 1: switch case in javascript

function whatToDrink(time){
    var drink ;
          switch (time) {
            case "morning":
              drink = "Tea";
              break;
            case "evening":
              drink = "Shake";
              break;
            default:
              drink="Water";   
          }
  	return drink;
}
console.log(whatToDrink("morning")) //Tea
console.log(whatToDrink("evening")) //Shake
console.log(whatToDrink("night"))   //Water
console.log(whatToDrink("daytime")) //Water

Example 2: switch case in js

var coll1="kjc;

switch(coll1)
{
  case "kjc":
    alert("youre special");
    break;
  case "horizon":
    alert("worst behaviour");
    break;
  case "cmr" :
    alert("worst character");
    break;
  default:
    alert("kjc is best");
    break;
}