meet it

Put something new in a box and the old thing is gone.

A box holds one value at a time. Store a new value and you the old one, like wiping a whiteboard. Leave out let this time: the box already exists, so you only change what is inside.

The + sign can two strings into one: "pop" + "corn" makes "popcorn". It adds no space, so put one inside the quotes if you need it.

Some values should never change, like your birthday. Make those boxes with instead of let. Try to overwrite one and JavaScript stops with a .

let mood = "sleepy";
mood = "happy";
console.log("I feel " + mood);
const birthday = "12 May";
console.log("My birthday is " + birthday);

Use let for boxes that will change and const for boxes that never will.

guess first

A locked box. What happens here?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

const pet = "Rex";
console.log(pet);
pet = "Max";
console.log(pet);

your turn

Your turn. Change the weather.

Line 3 puts a new value in the weather box. Type tomorrow's weather between the quotes, then press run.

Your code

press run to see what happens

fix it

The score will not update. Can you fix it?

Broken code to fix

press run to see what happens

Read the error. JavaScript is unhappy that the same box is being made twice.
let makes a brand new box. After line 1, the box called score already exists.
Remove let from line 2, so it reads score = 20; then press run.

nailed it

your boxes can change now. :D

A new value overwrites the old one. No second let.
+ joins strings, with no space added.
const boxes never change. Use let for ones that will.

new words in your collection

overwrite
join
const
TypeError

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