Java Tutorial - Data Type Conversions

This program explains type casting in Java:  

public class Main {

	public static void main(String[] args) {
		int someNumber = 10; //Starting Point
		float someFloat = someNumber;  //Automatic Casting - conversion - int to float		
		
		System.out.println(someNumber);
		System.out.println(someFloat);
		
		//Manual Casting
		
		double someDouble = 3.14; //Starting Point
		int newIntFromDouble = (int) someDouble;
		float newFloatFromInt = (float) newIntFromDouble;
		
		System.out.println(someDouble);
		System.out.println(newIntFromDouble);
		System.out.println(newFloatFromInt);
		
	}	
}

Line by line:

int someNumber = 10; //Starting Point

This line declares an integer variable named someNumber and initializes it to the value 10. 

float someFloat = someNumber;  //Automatic Casting - conversion - int to float

This line declares a floating-point variable named someFloat and assigns it the value of someNumber. This is an example of automatic casting, where the integer value is automatically converted to a floating-point value. 

System.out.println(someNumber);
System.out.println(someFloat);

These lines print the values of someNumber and someFloat to the console using the System.out.println() method. 

double someDouble = 3.14; //Starting Point
int newIntFromDouble = (int) someDouble;
float newFloatFromInt = (float) newIntFromDouble;

These lines declare a double-precision floating-point variable named someDouble and initialize it to the value 3.14.

The next line demonstrates manual casting, where the double value is cast to an int using the (int) syntax. The resulting int value is then assigned to a variable named newIntFromDouble.

The third line demonstrates another manual cast, where the int value is cast to a float using the (float) syntax. The resulting float value is then assigned to a variable named newFloatFromInt. 

System.out.println(someDouble);
System.out.println(newIntFromDouble);
System.out.println(newFloatFromInt);

These lines print the values of someDouble, newIntFromDouble, and newFloatFromInt to the console using the System.out.println() method.