gistfile1.js

function try_me (str) {
    switch (str) {
        case "foo": console.log("buu~"); break
        case "bar": console.log("baz~"); break
        default:    console.log("bad, bad argument, no cookies for you.") }
}

try_me("foo") // "buu~"
try_me("bar") // "baz~"
try_me("nou") // "bad, bad argument, no cookies for you."
try_me()      // "bad, bad argument, no cookies for you."