public/subjects/you-pass-butter/README.md

You pass butter

Return values

We are now going to see how to declare a function that returns a value.

Let's say we declare the variable ten the following way.

let ten = 5 + 5
console.log(ten) // 10

We could replace those 5 with a function that returns this value. Let's call this function returnsFive. The only new concept is the return keyword. It returns the specified value and stop the function execution.

let returnsFive = () => {
  return 5
  //     ↖ the keyword `return`, returns the value right after it,
  //       in this case the number 5.
}

Now that the function is declared, we call it where we need it.

let ten = returnsFive() + returnsFive()
console.log(ten) // 10

Now a question that you might ask yourself is: What if we had several return keywords in the same function ? Well as mentioned before, the return also stops the function execution. So only the first return would matter. In fact that means that anything after the return would not be executed. Example:

let returnsFive = () => {
  return 5 // ONLY this return is executed. Everything else is ignored.
  return 10 // not executed (useless)
  return 'I am useless' // not executed either
  console.log('I am also useless') // nor this one
}
let ten = returnsFive() + returnsFive()
console.log(ten) // 10
//exactly the same result as the previous example

As you may see, we get exactly the same result as the previous example. returnsFive only returns 5. :)

Instructions

As Rick's robot, you now know your purpose. (Remember ? 'You pass butter.')

Define the function passButter that returns the string 'The butter'.