🚀 Programming Example
Wrapper class Wrapping and Unwrapping
Learn this program step-by-step with algorithm, source code, output and detailed explanation.
public class WrappingUnwrapping
{
public static void main(String args[])
{
// data types
byte grade = 12;
int marks = 58;
float price = 9.6f; // observe a suffix of f for float
double rate = 60.5;
// data types to objects
Byte g1 = new Byte(grade); // wrapping
Integer m1 = new Integer(marks);
Float f1 = new Float(price);
Double r1 = new Double(rate);
// let us print the values from objects
System.out.println("Values of Wrapper objects (printing as objects)");
System.out.println("Byte object g1: " + g1);
System.out.println("Integer object m1: " + m1);
System.out.println("Float object f1: " + f1);
System.out.println("Double object r1: " + r1);
// objects to data types (retrieving data types from objects)
byte bv = g1.byteValue(); // unwrapping
int iv = m1.intValue();
float fv = f1.floatValue();
double dv = r1.doubleValue();
// let us print the values from data types
System.out.println("Unwrapped values (printing as data types)");
System.out.println("byte value, bv: " + bv);
System.out.println("int value, iv: " + iv);
System.out.println("float value, fv: " + fv);
System.out.println("double value, dv: " + dv);
}
}
Values of Wrapper objects (printing as objects)
Byte object g1: 12
Integer object m1: 58
Float object f1: 9.6
Double object r1: 60.5
Unwrapped values (printing as data types)
byte value, bv: 12
int value, iv: 58
float value, fv: 9.6
double value, dv: 60.5
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First understand the algorithm carefully. Then study the program line-by-line and compare it with the output. Finally, review the explanation section to strengthen your logic and programming understanding.
Rewrite the program without looking at the code. Modify values, conditions or logic and run it again. This helps improve confidence and strengthens coding skills much faster.