Year of the Dog explainer


Aim of the puzzle: Use the return keyword to return a value from a function.
Walk through of solution: The puzzle begins with two variables declared, dogName (a string) and dogAge (a number). Feel free to change the values of the two variables to a different string and number as you see fit.

The function lengthOfName() is also declared. This function takes a string, uses the .length string method to calculate the length of the string, and then returns that value using the return keyword.

The function ageInHumanYears() has also been declared. It takes an age (a number) and calculates age * 7, but is not yet using the return keyword. Because there is no return, the function will instead return undefined.

Try running the starter code when the puzzle loads. Because ageInHumanYears() does not have the return keyword, the following text will be printed to the console:

'The length of the name Pooky Mulder is 12 characters.'
'Pooky Mulder is undefined in human years.'

ageInHumanYears() is still performing the calculation age * 7, but it isn’t returning the answer, so undefined is being printed instead.

To complete the puzzle, replace age * 7 with return age * 7. Now when the program runs, the correct text will print to the console:

> 'The length of the name Pooky Mulder is 12 characters.'
> 'Pooky Mulder is 14 in human years.'

Because the return keyword has been added, the value of age * 7 can now be accessed outside the function.

Sample code solution:

let dogName = 'Pooky Mulder';
let dogAge = 2;

function lengthOfName(name) {
    return name.length;
function ageInHumanYears(age) {
    return age * 7;
console.log('The length of the name ' + dogName + ' is ' + lengthOfName(dogName) + ' characters.');
console.log(dogName + ' is ' + ageInHumanYears(dogAge) + ' in human years.');

Javascript Concepts: Return, Function Declarations, Variables with Let, String Methods



I cant make age * 7 to return age * 7. Someone explain me. I look to the hint but i cant nothing. This not replacing i try and i see only highlighted keyword return. in

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To turn age * 7 into return age * 7, you’ll need to delete the existing line of code and rewrite it starting with return.

I’ll see if we can update the app to allow return to be added to the beginning of a line.


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Where can I practice coding more? It is very difficult for me to understand some levels, however I really enjoy coding. I really to learn code, don’t know where to start.



There are some options in the app you might not have seen.

There is a Practice course that you can select from the main menu, on the left side. This is a course that grows as you solve more puzzles and helps you get more experience with code that you’ve already learned. This is a good place to go if you’ve taken a break and need a refresher.

There is also the Playground which is open ended. You can test out code and there isn’t any specific goal or feedback.


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