App Lab Quiz (Introduction)

What is App Lab used for?

• Writing long essays

• Building apps

• Watching videos

Answer explanation

App Lab is a platform to build and share apps.

Which of the following can you add in App Lab? (Choose all that apply)

• Buttons

• Images

• Sound

• Music streaming

Answer explanation

App Lab lets you use elements like buttons, images, and sound, but not streaming services.

What block is used to change an element's color, size, or text?

• playSound()

• setProperty()

• onEvent()

Answer explanation

setProperty() lets you modify an element’s properties like color and text.
⭐ Points: 1

Which property is needed to change the picture on the screen?

• "background"

• "image"

• "sound"

Answer explanation

You use the "image" property in setProperty() to show images

What do you need to create interaction (like clicking a button)?

• Use the setProperty() block

• Use the onEvent() block

• Use repeat() block

Answer explanation

onEvent() detects user actions like clicks.

Which line correctly sets the background color to "red"?

• setProperty("screen1", "background-color", red)

• setProperty("screen1", "background-color", "red")

• setProperty("screen1", background-color, "red")

Answer explanation

The color value needs to be in double quotes: "red"

Why is using good IDs important?

• To make the app run faster

• To find and control elements easily

• To reduce memory usage

Answer explanation

Good IDs help identify elements quickly in your code.

You want a button to show an image when clicked. What should you use? (Choose two)

• setProperty()

• onEvent()

• playSound()

• randomNumber()

Answer explanation

onEvent() detects the click, and setProperty() updates the image.

What happens if you forget to put quotes around a color name in setProperty()?

• The color will still change

• It will use a random color

• The program might not work

Answer explanation

App Lab needs strings like "blue" to be in quotes

What’s the purpose of Design Mode in App Lab?

• To write JavaScript code

• To debug your app

• To add and arrange screen elements

Answer explanation

Design Mode is used to create UI elements like buttons, images, etc