Math! Code-Along

Start by forking the JavaScript Starter Repl, then follow along as a group to perform a math experiment! You can name your fork something like Math! so it's easy for you to find later.

Set Up the Experiment

Click script.js to open the file in the Replit editor pane.

Write the code that will prompt the user for their favorite number between 1 and 9 and store their answer in a new variable named first.

let first = prompt("Enter your favorite number between 1 and 9:");

On the next line, ask the user for another number and store that answer in a new variable named second.

let second = prompt("Enter another number between 1 and 9:");

Perform the Experiment

Now that we have some input from the user, we can start to do some math!

First, simply concatenate (add) the first and second answers together and store that in a new variable named result1.

let result1 = first + second;

Next, use JavaScript's Number() function to convert the answers to numbers before adding them together. Store that value in a new variable: result2.

let result2 = Number(first) + Number(second);

Show the Results

Now that the math has been done, display the results in alert messages to the user.

alert("The results are in!");
alert("When we add your answers together as STRINGS, we get: " + result1);
alert("When we add your answers together as NUMBERS, we get: " + result2);

Save and run the page to test it out!

Expand the Experiment

Add a third result -- see what happens when you convert only one of the answers to a number.

let result3 = first + Number(second);

alert("When we convert only ONE of your answers to a number, we get: " + result3);

Final Code

The experiment is over.

However... to make it easier for you to understand your code later... you can add comments!

Some developers like to start a task by writing just the comments (like an essay outline) and then they'll fill in the code beneath each one. 🧠

// Set up the experiment
let first = prompt("Enter your favorite number between 1 and 9:");
let second = prompt("Enter another number between 1 and 9:");

// Perform the experiment
let result1 = first + second;
let result2 = Number(first) + Number(second);

// Show the results
alert("The results are in!");
alert("When we add your answers together as STRINGS, we get: " + result1);
alert("When we add your answers together as NUMBERS, we get: " + result2);

// Expand the experiment
let result3 = first + Number(second);
alert("When we convert only ONE of your answers to a number, we get: " + result3);

Bonus

Try switching to template strings if there is time. Did it make your code easier to read... or harder? 🤔