JavaScript Return Values: Understanding the Basics

In JavaScript, every function has a return value, even if it is not explicitly specified. By default, if no return statement is provided, the return value is undefined. However, you can use the return keyword to specify the value that should be returned.

For example:

const doSomething = () => {
  return 'test';
}

const result = doSomething(); // result === 'test'

In this example, the function doSomething returns the string 'test'. When we call the function and assign the result to the variable result, it will hold the value 'test'.

It is important to note that a function can only return one value. However, there are ways to simulate returning multiple values. One approach is to return an object literal from the function and then use destructuring assignment to access the individual values.

Using arrays:

const doSomething = () => {
  return ['value1', 'value2'];
}

const [value1, value2] = doSomething(); 

In this case, the function doSomething returns an array. By using destructuring assignment, we can assign the values from the array to variables value1 and value2.

Using objects:

const doSomething = () => {
  return { key1: 'value1', key2: 'value2' };
}

const { key1, key2 } = doSomething();

In this example, the function doSomething returns an object. We can then use destructuring assignment to extract the values associated with key1 and key2 from the returned object.

Understanding how return values work in JavaScript can help you write more effective and efficient code. Remember that a function can only return one value, but you can utilize objects or arrays to simulate returning multiple values when needed.