import java.util.Scanner;

public class BinaryAddition {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    System.out.print("Enter the first binary number: ");
    String binary1 = input.nextLine();
    System.out.println(binary1);

    System.out.print("Enter the second binary number: ");
    String binary2 = input.nextLine();
    System.out.println(binary2);

    int decimal1 = Integer.parseInt(binary1, 2);
    int decimal2 = Integer.parseInt(binary2, 2);
    int sum = decimal1 + decimal2;
    String binarySum = Integer.toBinaryString(sum);

    System.out.println("The sum of " + binary1 + " and " + binary2 + " is " + binarySum + " in binary and " + sum + " in decimal");

  }
}

BinaryAddition.main(null);

public class IntByValue {
    
    public static void changeInt(int n) {
        System.out.println("In changeInt method");
        System.out.println("\tBefore n += 10: n = " + n); // prints 5
        n = n += 10;
        System.out.println("\tAfter n += 10: n = " + n); // prints 10
    }

    public static void main(String[] args) {
        int n = 5;
        System.out.println("Main method before changeInt(n): n = " + n); // prints 5
        changeInt(n);
        System.out.println("Main method after changeInt(n): n = " + n); // still prints 5
    }
}
IntByValue.main(null);

public class IntegerByValueOrReference {
    
    public static void changeInteger(Integer n) {
        System.out.println("In changeInteger method");
        System.out.println("\tBefore change: n = " + 
                            n + // prints 5
                            " hash code = " + 
                            n.hashCode()); 

        n += 10;  // behind the scenes, this is:  n = new Integer(n+10)
        
        System.out.println("\tAfter change: n = " + 
                            n + // prints 15
                            " hash code = " + 
                            n.hashCode()); 
    }

    public static void main(String[] args) {
        Integer n = 5;
        System.out.println("Main method before changeInteger(n): n = " + 
                            n + // prints 5
                            " hash code = " + 
                            n.hashCode()); 

        changeInteger(n);
        
        System.out.println("Main method after changeInteger(n): n = " + 
                            n +  // now prints 15
                            " hash code = " + 
                            n.hashCode());     
    }
}
IntegerByValueOrReference.main(null);

import java.util.concurrent.atomic.AtomicInteger;

public class PassByReference {
    
    public static void changeAtomicInteger(AtomicInteger n) {
        System.out.println("In changeAtomicInteger method");
        System.out.println("\tBefore change: n = " + 
                            n + // prints 5
                            " hash code = " + 
                            n.hashCode()); 
        n.set(n.get() + 10);  // at this point, we are clearly working with reference data type
        System.out.println("\tAfter change: n = " + 
                            n + // prints 15
                            " hash code = " + 
                            n.hashCode()); 
}

    public static void main(String[] args) {
        AtomicInteger n = new AtomicInteger(5); // unlike conventional wrapper class, this requires new
        System.out.println("Main method before changeAtomicInteger(n): n = " + 
                            n + // prints 5
                            " hash code = " + 
                            n.hashCode()); 
        changeAtomicInteger(n);
        System.out.println("Main method after changeAtomicInteger(n): n = " + 
                            n +  // now prints 15
                            " hash code = " + 
                            n.hashCode()); 
    }
}
PassByReference.main(null);

public class IntByReference {
    private int value;

    public IntByReference(Integer value) {
        this.value = value;
    }

    public String toString() {
        return (String.format("%d", this.value));
    }

    public void swapToLowHighOrder(IntByReference i) {
        if (this.value > i.value) {
            int tmp = this.value;
            this.value = i.value;
            i.value = tmp;
        }
    }

    public static void swapper(int n0, int n1) {
        IntByReference a = new IntByReference(n0);
        IntByReference b = new IntByReference(n1);
        System.out.println("Before: " + a + " " + b);
        a.swapToLowHighOrder(b);  // conditionally build swap method to change values of a, b
        System.out.println("After: " + a + " " + b);
        System.out.println();
    }

    public static void main(String[] ags) {
        IntByReference.swapper(21, 16);
        IntByReference.swapper(16, 21);
        IntByReference.swapper(16, -1);
    }

}
IntByReference.main(null);

int[] numbers = {123, 456, 789};

for (int i = 0; i < numbers.length; i++) {
  String str = String.valueOf(numbers[i]);
  String subStr = str.substring(1, 2);
  int num = Integer.parseInt(subStr);
  System.out.println(num);
}

Integer[] numbers = {123, 456, 789};

for (int i = 0; i < numbers.length; i++) {
  String str = numbers[i].toString();
  String subStr = str.substring(1, 2);
  int num = Integer.parseInt(subStr);
  System.out.println(num);
}

int[] intArray = {1, 2, 3, 4, 5};

Integer[] integerArray = new Integer[intArray.length];
for (int i = 0; i < intArray.length; i++) {
    integerArray[i] = Integer.valueOf(intArray[i]);
}

double[] values = new double[5];

for (int i = 0; i < values.length; i++) {
  values[i] = Math.random();
  System.out.println(values[i]);
}

Double[] values = new Double[5];

for (int i = 0; i < values.length; i++) {
  values[i] = Math.random();
  System.out.println(values[i]);
}

boolean[] boolArray = {true, false, true};

for (int i = 0; i < boolArray.length; i++) {
  char c = boolArray[i] ? 'T' : 'F';
  System.out.println(c);
}

Boolean[] boolArray = {true, false, true};

for (int i = 0; i < boolArray.length; i++) {
  char c = boolArray[i] ? 'T' : 'F';
  System.out.println(c);
}

public static String toString(Double[] array) {
    StringBuilder sb = new StringBuilder();
    sb.append("[");
    for (int i = 0; i < array.length; i++) {
        sb.append(array[i].toString());
        if (i < array.length - 1) {
            sb.append(", ");
        }
    }
    sb.append("]");
    return sb.toString();
}