Java Part 1

Question 1

What are packages?

Answer 1

Used to group related classes and avoid naming clashes

Use import statement to tell the compiler where to find classes

Question 2

What are varargs?

Answer 2

Variable length arguments in a method declaration.
Must be last parameter
Elements passed in can be tuples or arrays

Question 3

What is inheritance?

Answer 3

Used between classes where there is a strong is-a relationship.
Implemented by using the extends keyword.

Question 4

What is an interface?

Answer 4

A class-like construct that is used to define behaviour

Can only have abstract methods and constants

Question 5

What are callback methods?

Answer 5

Method that are created by us that get called in the runtime.
onCreate(), onResume(), onStop()

Question 6

List types of errors.

Answer 6

Syntax,
Logic
Runtime

Question 7

What are the 3 states program can be in?

Answer 7

Design time
Run time
Break time

Question 8

What is a design time?

Answer 8

When you write or look at the code. The app is not running.

Question 9

What is a run time?

Answer 9

When a program is running and doing what it was meant to do.

Question 10

What is a break time?

Answer 10

When the program is in suspended animation. Statements are temporarily halted. Where debugging occurs.