2.5 - Return

Review

  • Computers take input, process it, and give output.

  • Code is run line-by-line, in the order you write it.

  • We can "chunk" code into smaller sub-programs called functions.

  • Functions can receive parameters in order to process given data.

Today's Lesson: 2.5 - Return (slides are here) (interactive video of the lesson is here!)

It's extremely convenient to pass arguments as parameters to a function:

let x = Math.pow(3, 6);
console.
log("3^6 is", x);

Q. How is Math.pow() giving an answer back?

Functions are not just a one-way process. They can return a value back for further processing. Let's recreate the Math.pow() function using the newly created double-star shortcut.

function pow(base, exponent) {
// The math is simple enough
let answer = base**exponent;

console.log(answer);

}

But that prints the answer to the console. Boring!
We want the answer back so we can use it.

That's where the statement return comes in.

function pow(base, exponent) {
let answer = base**exponent;

// Give the answer back to the caller
return answer;

}

Example: Using our new function

let example = pow(2, 3);
console.
log(example); // Prints 8
console.
log(pow(5, 4)); // Prints 625
console.log(pow(pow(2, 3), 2)); // Prints 64


Task 2.5

Return statements are easy to practice. Let's create lots of functions in the Replit project for 2.5.