javascript · level 1 · unit 7 · lesson 3
- meet it
- guess first
- your turn
- fix it
- nailed it
Tap a green word if you get lost.
meet it
hands the answer back so you can keep it.
So far your functions show things with console.log. Showing puts a value on the screen, and then it is gone. Your program cannot catch it, keep it or do maths with it.
To return a value, write return and the value. The call then turns into the answer, as if double(4) were the number 8. Store it, show it or use it again.
A function with no return hands back undefined, the same no-value you met with arrays.
function double(number) {
return number * 2;
}
let answer = double(4);
console.log(answer);
console.log(double(answer));Showing is letting someone see your answer, and return is handing it to them.
guess first
This one shows instead. What will appear?
Guess before you run it. Wrong guesses are how you learn, and nothing is marked.
function double(number) {
console.log(number * 2);
}
let answer = double(4);
console.log(answer);your turn
Your turn. Build a dog years machine.
In the first blank, type how many dog years each year counts as. People often say 7. In the second, type your dog's age, real or made up. Then press run.
fix it
Your score should double, but it stays at 5. Fix it!
- The function works and hands back 10. But does anything catch that answer?
- Line 5 calls double, but the returned value is dropped on the floor. Store it in the box.
- Change line 5 to score = double(score); then press run.
nailed it
your functions can hand back answers. :D
console.logshows a value.returnhands it back to use.- A function with no
returnhands backundefined. - Catch a returned value in a variable to keep it.
new words in your collection
- return
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