Why Javascript Functions Always Return A Value

When working with JavaScript, understanding how functions operate is fundamental. One common question that arises among beginners is why JavaScript functions always return a value. This concept might seem perplexing at first, but once you grasp it, your understanding of JavaScript will deepen significantly.

In JavaScript, every function, whether explicitly defined to return a value or not, will always return something. This key concept is crucial in grasping how functions work in JavaScript. Even if a function lacks a return statement, it will still return an 'undefined' value by default.

Let's delve deeper into this by considering an example:

function greet() {
  console.log("Hello, World!");
}
  
const result = greet();
console.log(result); // Output: undefined

In this example, our `greet` function simply logs a message to the console but does not return any value. When we call the `greet` function and store its result in the `result` variable, the `result` variable contains `undefined`. This illustrates the default return value of a function that does not explicitly return anything.

Now, let's consider another example of a function that explicitly returns a value:

function addNumbers(num1, num2) {
  return num1 + num2;
}

const sum = addNumbers(5, 3);
console.log(sum); // Output: 8

In this scenario, our `addNumbers` function takes two parameters, `num1` and `num2`, and returns their sum. When we call `addNumbers(5, 3)`, the returned value, which is the sum of `5` and `3`, is stored in the `sum` variable. This demonstrates how functions can explicitly return values using the `return` keyword.

Understanding that JavaScript functions always return a value, even if it is `undefined`, is vital for writing robust and predictable code. When you invoke a function, whether for its side effects or its return value, being aware of what it will yield helps you make informed decisions in your code.

Additionally, the concept of functions always returning a value underscores the versatility of functions in JavaScript. Functions can be used for computations, altering global state, interacting with the DOM, or generating output for further processing.

In conclusion, the fundamental principle that JavaScript functions always return a value, whether explicitly declared or not, is a cornerstone of JavaScript programming. Embracing this concept will enhance your proficiency in writing JavaScript code and enable you to harness the full potential of functions in your projects.

Keep exploring and experimenting with functions in JavaScript to deepen your understanding and elevate your coding skills. Happy coding!