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.
Return notes. 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.
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.
Tip In the V8 engine a special optimization is used to accelerate property lookups, so this approach is blazingly fast.
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.
Summary. Programs written in Node.js have many powerful features—functions can use multiple return values. We can use arrays or objects.
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
