Day 2

Question 1

What does it mean to initialize a variable?

Answer 1

It means giving a value to that variable

Question 2

Are constants variables or not?
How to define it?

Answer 2

• Yes. It’s a variable whose value can not be changed.
• “Final” keyword is used to define a constant.

Question 3

What’s the preferred convention used to name a constant?

Answer 3

We use Snake case convention where all words are in upper case and between each word we put an underscore.

Question 4

What’s an identifier in java?

Answer 4

It’s the naming. Generally any naming for classes, methods & variables. There are naming rules for identifiers.

Question 5

What are the only special characters allowed for identifiers?

Answer 5

$ dollar sign
_ underscore

Question 6

Which of these identifiers are correct according to rules?
1. Carrot6Piece
2. $diana
3. sad bitch
4. 2002best_year

Answer 6

1 & 2 are correct. Numbers are allowed within the identifier but not at the beginning

3 & 4 are wrong.
3. No spaces are allowed
4. Numbers are not allowed at the start of a name.

Question 7

What’s the difference between the following?
“@”
‘7’

Answer 7

”@” is a String.
‘7’ is a character. Character is a type of data.

Question 8

What type of data is True or False?

Answer 8

They are Booleans

Question 9

What type of data is a class?

Answer 9

Calsses can be considered of “User Defined Type” in which a programmer create their own data type.