return statement in JavaScript

Suppose we have a function that prints the square of the passed number to the console:

javascriptfunction func(num) {
  console.log(num ** 2);
}

Suppose we do not want to display the value to the console, but write it to some variable, like this:

javascriptlet res = func(3); // now there is 9 in the res variable  

To do this, JavaScript has a special instruction return, which allows you to specify the value that the function returns. The word "returns" means the value that will be written to the variable if the called function is assigned to it.

So, let's rewrite our function so that it does not print the result to the console, but returns it to a variable:

javascriptfunction func(num) {
  return num ** 2;
}

Let's call our function now, writing its response to a variable:

javascriptlet res = func(3); // 9 will be written to the variable

After the data is written to a variable, they can, for example, be output to the console:

javascriptlet res = func(3);
console.log(res); // shows 9

Or you can first somehow change this data, and then print it to the console:

javascriptlet res = func(3);
res = res + 1;
console.log(res); // shows 10

You can immediately perform some actions with the result of the function before writing to a variable:

javascriptlet res = func(3) + 1;
console.log(res); // shows 10

Or you can not write the result to a variable, but immediately print it to the console:

javascriptconsole.log(func(3)); // shows 9

You can invoke a function in one expression with different parameters:

javascriptlet res = func(2) + func(3);
console.log(res); // shows 13