FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -CheckBox. CheckBox components can detect user taps and can change their boolean state in response. A CheckBox component raises an event when the user taps it. There are many properties affecting its appearance that can be set in the Designer or Blocks Editor.

Detailed explanation-2: -Buttons are components that users touch to perform some action in your app. Buttons detect when users tap them. Many aspects of a button’s appearance can be changed. You can use the Enabled property to choose whether a button can be tapped.

Detailed explanation-3: -Human echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects, by actively creating sounds: for example, by tapping their canes, lightly stomping their foot, snapping their fingers, or making clicking noises with their mouths.

Detailed explanation-4: -Event Handlers App Inventor programs describe how the phone should respond to certain events: a button has been pressed, the phone is being shaked, the user is dragging her finger over a canvas, etc. This is specified by event handler blocks, which used the word when. E.g., when Button1.

Detailed explanation-5: -The components are chosen on the Design screen and dragged onto the phone. The user can then change properties of these components such as color, font, speed, etc. There are two main types of components: visible and non-visible. Visible components such as Button, TextBox, Label, etc.