Incrementing Variable

To increment a variable, set the variable equal to itself plus the amount to increment by. Example of incrementing a variable called age by 1:
age = age + 1

Exercise 1 of 6

Increase money by 1 when the button is clicked.

HTML

<button id="moneyButton">Increase money by 1</button>
<p id="moneyParagraph">Money: $0</p>

JavaScript

let moneyButton = document.getElementById(`moneyButton`)
let moneyParagraph = document.getElementById(`moneyParagraph`)

let money = 0

moneyButton.addEventListener(`click`, increaseMoney)

function increaseMoney() {
  // your code will appear here
  moneyParagraph.innerHTML = `Money: $${money}`
}

Your code

Test your code

Money: $0

Exercise 2 of 6

Increase score by 2 when the button is clicked.

HTML

<button id="scoreButton">Increase score by 2</button>
<p id="scoreParagraph">Score: 0</p>

JavaScript

let scoreButton = document.getElementById(`scoreButton`)
let scoreParagraph = document.getElementById(`scoreParagraph`)

let score = 0

scoreButton.addEventListener(`click`, increaseScore)

function increaseScore() {
  // your code will appear here
  scoreParagraph.innerHTML = `Score: ${score}`
}

Your code

Test your code

Score: 0

Exercise 3 of 6

Decrease points by 1 when the button is clicked.

HTML

<button id="pointsButton">Decrease points by 1</button>
<p id="pointsParagraph">Points: 0</p>

JavaScript

let pointsButton = document.getElementById(`pointsButton`)
let pointsParagraph = document.getElementById(`pointsParagraph`)

let points = 0

pointsButton.addEventListener(`click`, decreasePoints)

function decreasePoints() {
  // your code will appear here
  pointsParagraph.innerHTML = `Points: ${points}`
}

Your code

Test your code

Points: 0

Exercise 4 of 6

Increase width by 10 when the button is clicked.

HTML

<button id="increaseWidthButton">Increase width by 10</button>

JavaScript

let increaseWidthButton = document.getElementById(`increaseWidthButton`)

let width = 200

increaseWidthButton.addEventListener(`click`, increaseWidth)

function increaseWidth() {
  // your code will appear here
  increaseWidthButton.style.width = `${width}px`
}

Your code

Test your code

Exercise 5 of 6

Decrease opacity by 10 when the button is clicked.

HTML

<button id="decreaseOpacityButton">Decrease opacity by 10</button>

JavaScript

let decreaseOpacityButton = document.getElementById(`decreaseOpacityButton`)

let opacity = 100

decreaseOpacityButton.addEventListener(`click`, decreaseOpacity)

function decreaseOpacity() {
  // your code will appear here
  decreaseOpacityButton.style.opacity = `${opacity}%`
}

Your code

Test your code

Exercise 6 of 6

Double the number when the button is clicked.

HTML

<button id="numberButton">Double the number</button>
<p id="numberParagraph">Number: 1</p>

JavaScript

let numberButton = document.getElementById(`numberButton`)
let numberParagraph = document.getElementById(`numberParagraph`)

let number = 1

numberButton.addEventListener(`click`, doubleNumber)

function doubleNumber() {
  // your code will appear here
  numberParagraph.innerHTML = `Number: ${number}`
}

Your code

Test your code

Number: 1