Multiple return values

Some functions return just one value—they return a string or an integer. But others functions in Node.js return many things—an assortment of values.

With an array, or an object, we can return multiple values. We can return any number of values from a function, but special syntax is needed.

Array example

An array can hold any number of elements. We can return an array from a function. We put our multiple return values in the array.

function importantValues() {
    // Return 3 values in an array.
    return [1, 2, "cat"];
}

var result = importantValues();
console.log("RETURN VALUE 1: " + result[0]);
console.log("RETURN VALUE 2: " + result[1]);
console.log("RETURN VALUE 2: " + result[2]);
RETURN VALUE 1: 1
RETURN VALUE 2: 2
RETURN VALUE 2: cat

Object

With an object we can reference return values by name. This approach may be clearer to read. The return values are labeled.

function petValues() {
    // Return multiple values in an object.
    return {animal: "cat",
        size: 100,
        color: "orange",
        name: "fluffy"};
}

var pet = petValues();
console.log("RETURN VALUE: " + pet.animal);
console.log("RETURN VALUE: " + pet.size);
RETURN VALUE: cat
RETURN VALUE: 100

Strict mode

As a reminder, the "use strict" directive can prevent errors in functions. It can help us avoid "sloppy" global variable creation in functions.

Programs written in Node.js have many powerful features—functions can use multiple return values. We can use arrays or objects.