Java Practical Pro

Ruler.java

public class Ruler 

{ 

 public static void main(String[] args)

 { 

        String ruler1 = " 1 ";

        String ruler2 = ruler1 + "2" + ruler1;

        String ruler3 = ruler2 + "3" + ruler2;

        String ruler4 = ruler3 + "4" + ruler3;

        String ruler5 = ruler4 + "5" + ruler4;

        System.out.println(ruler1);

        System.out.println(ruler2);

        System.out.println(ruler3);

        System.out.println(ruler4);

        System.out.println(ruler5);

    }

}

IntOps.java

public class IntOps 

{ 

           public static void main(String[] args) 

{

        int a = Integer.parseInt(args[0]);

        int b = Integer.parseInt(args[1]);

        int sum  = a + b;

        int prod = a * b;

        int quot = a / b;

        int rem  = a % b;

        System.out.println(a + " + " + b + " = " + sum);

        System.out.println(a + " * " + b + " = " + prod);

        System.out.println(a + " / " + b + " = " + quot);

        System.out.println(a + " % " + b + " = " + rem);

        System.out.println(a + " = " + quot + " * " + b + " + " + rem);

    }

}

Quadratic.java

public class Quadratic 

{ 

public static void main(String[] args) 

{ 

        double b = Double.parseDouble(args[0]);

        double c = Double.parseDouble(args[1]);

        double discriminant = b*b - 4.0*c;

        double sqroot =  Math.sqrt(discriminant);

        double root1 = (-b + sqroot) / 2.0;

        double root2 = (-b - sqroot) / 2.0;

        System.out.println(root1);

        System.out.println(root2);

    }

}

LeapYear.java

public class LeapYear 

{ 

 public static void 0main(String[] args) 

{ 

        int year = Integer.parseInt(args[0]);

        boolean isLeapYear;

                  isLeapYear = (year % 4 == 0);

                  isLeapYear = isLeapYear && (year % 100 != 0);

        isLeapYear = isLeapYear || (year % 400 == 0);

                  System.out.println(isLeapYear);

    }

}

RandomInt.java

public class RandomInt 

{ 

public static void main(String[] args) 

{ 

        int N = Integer.parseInt(args[0]);

        double r = Math.random();

        int n = (int) (r * N);

                     System.out.println("Your random integer is: " + n);

    }

}