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Code Studio · Level 2

Real JavaScript Variables

Build a basketball game with JavaScript variables. Store team names, scores, fouls, the period, and possession, then run the code to bring the scoreboard to life.

15-20 min Ages 9-12 Real Code JavaScript

What is a variable?

A variable is like a labeled box. You write a name on the outside, put a value inside, and close the lid. From then on, whenever your code uses the name on the label, the computer opens the box and grabs whatever is inside. The label stays the same — but you can swap what's in the box any time.

"Comets" homeTeam
  1. 1

    Make the box: let homeTeam = "Comets";

    let tells JavaScript "make a new box." homeTeam is the label you write on it. = means "put this inside," and "Comets" is the value that goes in the box.

  2. 2

    Use the label, get what's inside

    say(homeTeam) displays Comets — not "homeTeam." There are no quotes around it, so the computer knows it's a box label and opens the box to find the value.

  3. 3

    Why coders use them

    Variables let a program remember things — a player's name, a score, a team name. And if your home team's name appears 20 times in a game, you only change the box once and every spot updates. Try it: change homeTeam or homeScore and run the code again.

Code Editor

Code a basketball scoreboard.

Choose values for your game. Each choice becomes a real JavaScript variable.

Change the controls or edit the generated code below. Press Run Code to start the game.

Output

Basketball game

Basketball scoreboard 02:18 COMETS ROCKETS 42 39 3 3 4 ◀
Basketball hoop Basketball Press Run Code!

Type real JavaScript, then run it.