Basic Java Programming

Question 1

Name the types of data types in Java.

Answer 1

1. Primitive data types used to store simple values
2. Refernce data types used to store the address of Objects

Question 2

What is the fomular for calculating range of values for number data types?

Answer 2

-2^n-1 to 2^n-1 -1

where n is the number of bits for each data type

Question 3

Name all number data types and the bits for each type.

Answer 3

byte => 8 bits
short => 16 bits
int => 32bits
long => 64bits

Question 4

Name all the floating point datatypes and the number of bits for each

Answer 4

float => 32 bits
double => 64 bits

Question 5

How many bits are booleans, and char’s?

Answer 5

boolean => 1 bit
char => 16 bits

Question 6

Name a few reference datypes?

Answer 6

Classes
Strings
Arrays
Interfaces

Question 7

What are the type of variables in Java?

Answer 7

1. Local variables: variables that exist only within a block or method
2. Instance variables: Variables that belong to an object or class and are not static
3. Static variables: Variables shared accross all objects
4. Parameters: Parameters in Java are variables in a method that receive values when the method is called. They act as inputs for the method to work with.

Question 8

What are the different types of operators in Java?

Answer 8

1. Arithmetic
2. Logical
3. Relational

Question 9

name 3 types of loops in Java

Answer 9

for, while, and do while

Question 10

What is the syntax for creating a forEach loop in java?

Answer 10

String[] names = {“john”, “james”};

    for(String name : names){
        System.out.println(name);
    }