The return operator in Javascript
The return operator in JavaScript is used to return a value from a function. When the interpreter encounters a return, the function execution stops, and control returns to where the function was called. If a value is specified after return, it is returned as the result of the function.
return can return any value: a number, string, object, array, other function, and even null or undefined.
As soon as the return is executed, the function immediately completes its work. The code that is after the `return’ is not executed.
If return is used without a value, the function returns undefined.
function functionName() {
// Function code
return value;
// Return the value and end the function
}
Returning a number:
function sum(a, b) {
return a + b; // Returns the sum of a and b
}
const result = sum(2, 3); // result = 5
console.log(result); // Outputs: 5
String Return:
function greet(name) {
return "Hello, " + name +"!";
}
const message = greet("Elle"); // message = "Hello, Elle!"
console.log(message); // Outputs: "Hello, Elle!"
Object return:
function createUser(name, age) {
return { name: name, age: age }; // Returns an object
}
const user = createUser("Mia", 25);
console.log(user); // Outputs: { name: "Mia", age: 25 }
Return without value:
function doSomething() {
console.log("Doing something...");
return; // The function terminates, returns undefined
console.log("This code will not execute");
}
const result = doSomething(); // result = undefined
console.log(result); // Outputs: undefined
return can be used to terminate a function early if no further code execution is required.
function checkAge(age) {
if (age < 18) {
return "Access denied"; // The function ends if age < 18
}
return "Access allowed"; // Executed if age >= 18
}
console.log(checkOut(15)); // Outputs: "Access denied"
console.log(checkOut(20)); // Outputs: "Access is allowed"
Using return makes functions more flexible and powerful, allowing them to interact with the rest of the code.