switch statements

A switch statement allows you to execute different blocks of code based on the value of a variable. It’s an alternative to using multiple if else statements when you’re checking one variable against several possible values.

How it works:

1. The switch expression is evaluated once
2. The value of the expression of compared with the values of each case
3. If there is a match, the associated code black is executed
4. If there is no match, the default code block is executed

switch (expression) {
  case x: // If expression === x
    // code block
    break;
  case y: // Else if expression === y
    // code block
    break;
  default: // Else
    // code block
}

let weather = "Sunny";

if (weather === "Windy") {
  console.log("Wear a jacket!");
} else if (weather === "Rainy") {
  console.log("Bring an umbrella!");
} else if (weather === "Sunny") {
  console.log("Put sunscreen on!"); 
} else {
  console.log("Unknown weather");  
}

// check the value of the weather variable and execute different code 
// based on which weather it is
let weather = "Sunny";

switch (weather) {
  case "Windy":
    console.log("Wear a jacket!");
    break;
  case "Rainy":
    console.log("Bring an umbrella!");
    break;
  case "Sunny":
    console.log("Put sunscreen on!");
    break;
  default:
    console.log("Unknown weather");
}

default case

The default keyword specifies the code to run if there is no case match. It is not necessary to break the last case in a switch block since the block breaks ends there anyway.

potion = "healing"; // try changing this to other values
if (potion === "healing") {
  console.log("Restores health!");
} else if (potion === "invisibility") {
  console.log("You disappear!");
} else if (potion === "strength") {
  console.log("You feel powerful!");
} else if (potion === "poison") {
  console.log("Ouch! Toxic!");
} else {
  console.log("Unknown potion!");
}