Week 1 - Intro to Java

Question 1

Write a program that prints out “Hello World!”

Answer 1

public class HelloWorld {
—-public static void main ( String[] args) {
——–System.out.println(“Hello World!”);
—–}
}

Question 2

What to main types does Java have?

Answer 2

Primitive types

Non-Primitive types/Classes

Question 3

What are the primitive types?

Answer 3

• boolean - true/false
• char - ‘A’ ‘6’
• int - whole number
• short - small whole number
• long - larger whole number
• float - decimal number
• double - high precision float

Question 4

What are the non-primitive types?

Answer 4

• Classes
• Arrays
• Strings
• Interfaces

Question 5

What is scope of a variable?

Answer 5

Scope is where a variable can be used in a script. A variable can only be used inside the block in which it was declared.

Question 6

How do you create a variable?

Answer 6

In java variables have both a type and a name, so all variables must be declared before use.

int x;

int defines the type of variable and x is the name of the variable.