Node.js by Example: Switch

Switch statements evaluate expressions and match to a specific case.

Here’s a basic switch statement. break is required in order to not fall into the below case.

let i = 2;
let str = "Write " + i + " as ";
switch (i) {
    case 1:
        str += "one";
        break;
    case 2:
        str += "two";
        break;
    case 3:
        str += "three"
        break;
}
console.log(str);

Another example using default to handle any case not matched.

const whatAmI = i => {
    switch (typeof i) {
        case "boolean":
            console.log("I'm a bool");
            break;
        case "number":
            console.log("I'm a number");
            break;
        case "string":
            console.log("I'm a string");
            break;
        default:
            console.log("Don't know type", typeof i);
    }
}
whatAmI(true);
whatAmI(1);
whatAmI("hey");
whatAmI(null);

$ node switch.js
Write 2 as two
I'm a bool
I'm a number
I'm a string
Don't know type object

Next example: Functions.