Primitive Data Types
In your personal blog you should have a comprehensive example that help you recall Primitive Data Types.
public class PrimitiveTypesDemo {
public static void main(String[] args) {
// Declare and initialize variables of different primitive types
byte myByte = 10; // 8-bit integer
short myShort = 32000; // 16-bit integer
int myInt = 123456; // 32-bit integer
long myLong = 123456789L; // 64-bit integer
float myFloat = 3.14f; // 32-bit floating-point
double myDouble = 3.14159; // 64-bit floating-point
char myChar = 'A'; // 16-bit Unicode character
boolean myBoolean = true; // true or false
// Perform some operations
int sum = myInt + 1000;
float division = myFloat / 2;
boolean isEqual = myByte == 10;
// Print the results
System.out.println("Byte value: " + myByte);
System.out.println("Short value: " + myShort);
System.out.println("Int value: " + myInt);
System.out.println("Long value: " + myLong);
System.out.println("Float value: " + myFloat);
System.out.println("Double value: " + myDouble);
System.out.println("Char value: " + myChar);
System.out.println("Boolean value: " + myBoolean);
System.out.println("Sum of myInt and 1000: " + sum);
System.out.println("Division of myFloat by 2: " + division);
System.out.println("Is myByte equal to 10? " + isEqual);
}
}
PrimitiveTypesDemo.main(null);
Byte value: 10
Short value: 32000
Int value: 123456
Long value: 123456789
Float value: 3.14
Double value: 3.14159
Char value: A
Boolean value: true
Sum of myInt and 1000: 124456
Division of myFloat by 2: 1.57
Is myByte equal to 10? true
Refrence Types Examples
In your Personal Blog you should create a class that captures key reference type in Java. In fact, there is at least one common reference type we will be testing on in AP CSA that is not represented below.
class Person {
// Fields (attributes) of the Person class
String name;
int age;
// Constructor to initialize the Person object
Person(String name, int age) {
this.name = name;
this.age = age;
}
// Method to introduce the person
void introduce() {
System.out.println("Hello, my name is " + name + " and I am " + age + " years old.");
}
// Method to simulate having a birthday
void haveBirthday() {
age++;
System.out.println("Happy Birthday! I am now " + age + " years old.");
}
}
public class ReferenceTypesDemo {
public static void main(String[] args) {
// Create an instance of the Person class (a custom reference type)
Person person = new Person("John", 25);
// Call methods on the Person object
person.introduce();
person.haveBirthday();
// Create and initialize an array of integers
int[] numbers = {1, 2, 3, 4, 5};
// Print the contents of the integer array
System.out.println("Array contents:");
for (int number : numbers) {
System.out.println(number);
}
// Create and initialize a 2D array of strings
String[][] matrix = {
{"A1", "B1", "C1"},
{"A2", "B2", "C2"},
{"A3", "B3", "C3"}
};
// Print the contents of the 2D string array
System.out.println("2D array contents:");
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix[i].length; j++) {
System.out.print(matrix[i][j] + " ");
}
System.out.println();
}
}
}
ReferenceTypesDemo.main(null);
Hello, my name is John and I am 25 years old.
Happy Birthday! I am now 26 years old.
Array contents:
1
2
3
4
5
2D array contents:
A1 B1 C1
A2 B2 C2
A3 B3 C3