Return from function

And what if we need to get a value from a function and somehow use it later?

Functions are able to return the result of their work. We already talked about what “return” means in “Introduction to JavaScript” chapter. Take a look there if you forgot what “return” is and how it works.

Briefly, the function can execute the code and return the result of its actions for further use. This result is placed into the position where we called the function.

var increaseByTwo = function (number) {
  var sum = 2 + number;
  return sum;
};

increaseByTwo(1); // Function will return 3
increaseByTwo(2); // Function will return 4

How does this code works?

To return a value, we use the return statement. Then we specify a return value after the statement. In our case, it is a value of the variable sum. When the function reaches the line return, it returns the result and completes the code execution, in other words, we will exit the function.

A few things you need to know:

• Code written on a new line after return is not executed.
• A function cannot return many values ​​at once, it returns only one result.
• If there is no return inside the function or if after return the return value is not specified, the function will return undefined, in other words, nothing.

As we mentioned above, the result of function actions can be used for further operations.

console.log('Sum of numbers: ' + increaseByTwo(1));
// Displays: Sum of numbers: 3

console.log('Sum of numbers: ' + increaseByTwo(2));
// Displays: Sum of numbers: 4

JavaScript has built-in language functions that return the result of their work. There are a lot of such functions, and here are just a few of them:

• Math.ceil(number) accepts the input number and rounds it up to a whole number.
• Math.floor(number) does the same, only rounds it down.
• Math.round (number) rounds the number to the nearest integer value.

Round the number of miles in our calculateMiles function. Where did you see a fractional number of miles being accrued?