4. Program to Accept value of Radius and Calculate Area of Circle.

class CalculateCircleAreaExample
{

public static void main(String[] args)
{

int radius = 3;
System.out.println("The radius of the circle is " + radius);

/*
* Area of a circle is pi * r * r where r is a radius of a circle.
*/

// NOTE : use Math.PI constant to get value of pi
double area = Math.PI * radius * radius;

System.out.println("Area of a circle is " + area);
}
}

@java_codings

5. Program to Accept value of length & width and Calculate Area of Rectangle.

import java.util.Scanner;

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

System.out.println("Enter the length of Rectangle:");
double length = scanner.nextDouble();

System.out.println("Enter the width of Rectangle:");
double width = scanner.nextDouble();

//Area = length*width;
double area = length * width;

System.out.println("Area of Rectangle is:" + area);
}
}

@java_codings

6. Program to Accept value of the side of Square and Calculate Area of Square.

import java.util.*;

class AreaOfSquare
{
public static void main(String args[])
{
int side, area;

Scanner sc = new Scanner(System.in);

System.out.println("Enter value of the sides of square");
side = sc.nextInt();

area = side * side;

System.out.println("Area of Square : " + area);
}
}

@java_codings

7. Program to Calculate Area's.

import java.util.Scanner;

class AreaCalculator
{

float l, b, h, r, ba, s, c;
float result = 0f;
float pi = 3.14f;
int var;
public static void main(String[] args)
{
AreaCalculator ar = new AreaCalculator();
ar.options();
}

public void options()
{
Scanner a = new Scanner(System.in);
System.out.println("Enter the Object of which Area is to be calculated \n1:square \n2:rectangle \n3:Triangle\n4:circle\n5:Trapezoid\n6:Repeat\n7:Exit");

var = a.nextInt();
Area a1 = new Area();

if (var == 1)
{
System.out.println("Enter the Side of Square");
s = a.nextFloat();
a1.square(s);
options();
}

else if (var == 2)
{
System.out.println("Enter the Length of Rectangle");
l = a.nextFloat();
System.out.println("Enter the Breadth of Rectangle");
b = a.nextFloat();
a1.rectangle(l, b);
options();
}

else if (var == 3)
{
System.out.println("Enter the Height of Triangle");
h = a.nextFloat();
System.out.println("Enter the Base of Triangle");
ba = a.nextFloat();
a1.triangle(h, ba);
options();
}

else if (var == 4)
{
System.out.println("Enter the Radius of Circle");
r = a.nextFloat();
a1.circle(r);
options();
}

else if (var == 5)
{
System.out.println("Enter the A side of Trapezoid");
b = a.nextFloat();
System.out.println("Enter the B side of Trapezoid");
c = a.nextFloat();
System.out.println("Enter the Height of Trapezoid");
h = a.nextFloat();
a1.trapezoid(b, c, h);
options();
}
}
}

class Area
{
public void square(float s)
{
float result = 0f;
result = s * s;
System.out.println("The Area of Square is :" + result);
}

public void rectangle(float l, float b)
{
float result = 0f;
result = l * b;
System.out.println("The Area of Rectangle is :" + result);
}

public void triangle(float h, float ba)
{
float result = 0f;
result = 0.5f * h * ba;
System.out.println("The Area of Triangle is :" + result);
}

public void circle(float r)
{
float result = 0f;
result = 3.14f * (r * r);
System.out.println("The Area of Circle is :" + result);
}

public void trapezoid(float b, float c, float h)
{
float result = 0f;
result = (((b + c) / 2) * h);
System.out.println("The Area of Trapezoid is :" + result);
}
}

@java_codings

8. Program to Find Simple Interest and Compound Interest.

import java.lang.*;
import java.util.Scanner;

class CalculateInterest
{
public static void main(String[] args)
{
double p, n, r, si, ci;

Scanner s = new Scanner(System.in);

System.out.print("Enter the amount : ");
p = s.nextDouble();

System.out.print("Enter the No.of years : ");
n = s.nextDouble();

System.out.print("Enter the Rate of interest : ");
r = s.nextDouble();

si = (p * n * r) / 100;
ci = p * Math.pow(1.0 + r / 100.0, n) - p;

System.out.println("\nAmount : " + p);
System.out.println("No. of years : " + n);
System.out.println("Rate of interest : " + r);
System.out.println("Simple Interest : " + si);
System.out.println("Compound Interest : " + ci);
}
}

@java_codings

9. Program to Calculate Binary Number Calculation.

import java.util.*;

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

System.out.print("First Binary: ");
String binOne = in.next();

System.out.print("Second Binary: ");
String binTwo = in.next();

int left = Integer.parseInt(binOne, 2);
int right = Integer.parseInt(binTwo, 2);

System.out.println("Sum of the binary numbers : " + Integer.toBinaryString(left + right));
System.out.println("Difference of the binary numbers : " + Integer.toBinaryString(left - right));
System.out.println("Product of the binary numbers : " + Integer.toBinaryString(left * right));
System.out.println("Quotient of the binary numbers : " + Integer.toBinaryString(left / right));
}
}

@java_codings

10. Program to Convert Celsius to Fahrenheit.

import java.util.*;

class CelsiustoFahrenheit
{
public static void main(String[] args)
{
double temperature;
Scanner in = new Scanner(System.in);

System.out.println("Enter temperature in Celsius");
temperature = in.nextInt();

temperature = (temperature * 9 / 5.0) + 32;
System.out.println("Temperature in Fahrenheit = " + temperature);
}
}

@java_codings

11. Program to Create a Simple Calculator.
import java.util.Scanner;
import java.io.*;
class Calculator
{
public static void main(String[] args)
{
int choice;
int x = 0;
int y = 0;
int sum;
PrintStream out;
Scanner input;
Calculator calc = new Calculator();
try
{
out = new PrintStream("calclog.txt");
do
{
System.out.println("Calculator Program"); System.out.println("--------------------\n");
System.out.println("1. Add");
System.out.println("2. Subtract");
System.out.println("3. Multiply");
System.out.println("4. Divide");
System.out.println("5. Mod");
System.out.println("6. Power");
System.out.println("99. End Program\n");
System.out.println("Enter Choice: ");
input = new Scanner(System.in);
choice = input.nextInt();
while ((choice < 1 || choice > 6) && choice != 99)
{
System.out.println("Please enter 1, 2, 3, 4, 5, or 6: ");
choice = input.nextInt();
}
if (choice != 99)
{
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
}
switch (choice)
{
case 1:
sum = calc.add(x, y);
System.out.printf("The sum is %d\n\n", sum);
out.println(x + "+" + y + "=" + sum);
break;
case 2:
sum = calc.sub(x, y);
System.out.printf("The answer is %d\n\n", sum);
out.println(x + "-" + y + "=" + sum);
break;
case 3:
sum = calc.multi(x, y);
System.out.printf("The answer is %d\n\n", sum);
out.println(x + "*" + y + "=" + sum);
break;
case 4:
try
{
sum = calc.div(x, y);
System.out.printf("The answer is %d\n\n", sum);
out.println(x + "/" + y + "=" + sum);
}
catch (Exception e)
{
System.out.println("\nError: Cannot Divide by zero\n\n");
}
break;
case 5:
sum = calc.mod(x, y);
System.out.printf("The mod is %d\n\n", sum);
out.println(x + "%" + y + "=" + sum);
break;
case 6:
sum = calc.pow(x, y)
System.out.printf("The answer is %d\n\n", sum);
out.println(x + "^" + y + "=" + sum);
break;
}
}
while (choice != 99);
input.close();
System.out.println("Ending program...");
}
catch (Exception e){
System.out.println("ERROR: Some error occured");
e.printStackTrace();
}
}
public int add(int num1, int num2)
{int sum;
sum = num1 + num2;
return sum;
}
public int sub(int num1, int num2)
{ int sum;
sum = num1 - num2;
return sum;
}
public int multi(int num1, int num2)
{ int sum;
sum = num1 * num2;
return sum;
}
public int div(int num1, int num2)
{int sum;
sum = num1 / num2;
return sum;
}
public int mod(int num1, int num2)
{int sum;
sum = num1 % num2;
return sum;
}
public int pow(int base, int exp)
{int sum = 1;
if (exp == 0)
{sum = 1;
}
while (exp > 0)
{sum = sum * base;
exp--;
}
return sum;
}
}
@java_codings

12. Program to Calculate Mean.

import java.util.Scanner;

class CalculateMean
{

public static void main(String[] args)
{

int sum = 0, inputNum;
int counter;
float mean;
Scanner NumScanner = new Scanner(System.in);

System.out.println("Enter the total number of terms whose mean you want to calculate");

counter = NumScanner.nextInt();

System.out.println("Please enter " + counter + " numbers:");

for (int x = 1; x <= counter; x++)
{
inputNum = NumScanner.nextInt();
sum = sum + inputNum;
System.out.println();
}

mean = sum / counter;
System.out.println("The mean of the " + counter + " numbers you entered is " + mean);
}
}

@java_codings

13. Program to Convert Binary to Decimal.

import java.io.*;

class BinaryToDecimal
{
public static void main(String[] args) throws Exception
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter Binary no. to convert in Decimal : ");
String number = br.readLine();

/*
to convert Binary number to decimal number use,
int parseInt method of Integer wrapper class.

Pass 2 as redix second argument.
*/

int decimalNumber = Integer.parseInt(number, 2);
System.out.println("Binary number converted to decimal number");
System.out.println("Decimal number is : " + decimalNumber);

}
}

@java_codings

14. Program to Convert Binary to Octal.

import java.io.*;

class BinaryToOctal
{
public static void main(String[] args) throws Exception
{
String num = null;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

System.out.print("Enter binary number : ");
num = br.readLine();
int dec = Integer.parseInt(num, 2);

String oct = Integer.toOctalString(dec);

System.out.println("Binary " + num + " in Octal is " + oct);

}
}

@java_codings

15. Program to Convert Decimal to Binary.

import java.util.Scanner;

class DecimalToBinary
{

public String toBinary(int n)
{
if (n == 0)
{
return "0";
}

String binary = "";
while (n > 0)
{
int rem = n % 2;
binary = rem + binary;
n = n / 2;
}

return binary;
}

public static void main(String[] args)
{
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number: ");
int decimal = scanner.nextInt();

DecimalToBinary decimalToBinary = new DecimalToBinary();
String binary = decimalToBinary.toBinary(decimal);

System.out.println("The binary representation is " + binary);
}
}

@java_codings

16. Program to Find Fraction Addition.

import java.util.*;

class FractionAdding
{
public static void main(String args[])
{
float a, b, c, d;
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a : ");
a = scanner.nextFloat();
System.out.print("Enter b : ");
b = scanner.nextFloat();
System.out.print("Enter c : ");
c = scanner.nextFloat();
System.out.print("Enter d : ");
d = scanner.nextFloat();

// fraction addition formula ((a*d)+(b*c))/(b*d)
System.out.print("Fraction Addition : [( " + a + " * " + d + " )+( " + b + " * " + c + " ) / ( " + b + " * " + d + " )] = " + (((a * d) + (b * c)) / (b * d)));
}
}

@java_codings

17. Program to Find Fraction Subtraction.

import java.util.*;

class FractionSubtraction
{
public static void main(String args[])
{
float a,b,c,d;
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a : ");
a = scanner.nextFloat();
System.out.print("Enter b : ");
b = scanner.nextFloat();
System.out.print("Enter c : ");
c = scanner.nextFloat();
System.out.print("Enter d : ");
d = scanner.nextFloat();

// fraction addition formula ((a*d)-(b*c))/(b*d)
System.out.print("Fraction subtraction : [( "+a+" * "+d+" )-( "+b+" * "+c+" ) / ( "+b+" * "+d+" )] = "+(((a*d)-(b*c))/(b*d)));
}
}

@java_codings

18. Program to Find GCDLCM.

import java.util.Scanner;

class GCDLCM
{
public static void main(String args[])
{
int x, y;
Scanner sc = new Scanner(System.in);

System.out.println("Enter the two numbers: ");
x = sc.nextInt();
y = sc.nextInt();

System.out.println("GCD of two numbers is : " + gcd(x, y));
System.out.println("LCM of two numbers is : " + lcm(x, y));
}

static int gcd(int x, int y)
{
int r = 0, a, b;
a = (x > y) ? x : y; // a is greater number
b = (x < y) ? x : y; // b is smaller number

r = b;
while (a % b != 0)
{
r = a % b;
a = b;
b = r;
}
return r;
}

static int lcm(int x, int y)
{
int a;
a = (x > y) ? x : y; // a is greater number
while (true)
{
if (a % x == 0 && a % y == 0)
{
return a;
}
++a;
}
}
}

@java_codings

19. Program to Find Harmonic Series.

import java.util.*;

class HarmonicSeries
{

public static void main(String args[])
{

int num, i = 1;
double rst = 0.0;

Scanner in = new Scanner(System.in);
System.out.println("Enter the number for length of series");
num = in.nextInt();

while (i <= num)
{

System.out.print("1/" + i + " +");
rst = rst + (double) 1 / i;

i++;
}

System.out.println("\n\nSum of Harmonic Series is " + rst);
}
}

@java_Codings

20. Program to Create Multiplication Table.

import java.util.Scanner;

class MultiplicationTable
{

public static void main(String args[])
{

int n, c;
System.out
.println("Enter an integer to print it's multiplication table");

Scanner in = new Scanner(System.in);
n = in.nextInt();
System.out.println("Multiplication table of " + n + " is :-");

for (c = 1; c <= 10; c++)
{
System.out.println(n + "*" + c + " = " + (n * c));
}

}
}

@Cpp_Codings

21. Alphabet Pattern
A
BB
CCC
DDDD
EEEEE

import java.util.*;

class AlphabetPattern
{
public static void main(String[] arg)
{
int line, row, col;
char ch = 'A';
Scanner scanner = new Scanner(System.in);
System.out.print("Enter number of lines : ");
line = scanner.nextInt();

for (row = 1; row <= line; row++)
{
for (col = 1; col <= row; col++)
{
System.out.print("" + ch);
}
System.out.println();
ch++;
}
}
}

@java_Codings

22. Binary Pattern
1
01
101
0101
10101

class BinaryPattern
{
public static void main(String s[])
{
int i, j;
int count = 1;
for (i = 1; i <= 5; i++)
{
for (j = 1; j <= i; j++)
{
System.out.format("%d", count++ % 2);
if (j == i && i != 5)
System.out.println("");
}

if (i % 2 == 0)
count = 1;
else
count = 0;
}
}
}

@java_Codings

23. Christmas tree.

class ChristmasTree
{
public static final int segments = 4;
public static final int height = 4;

public static void main(String[] args)
{
makeTree();
}

public static void makeTree()
{
int maxStars = 2 * height + 2 * segments - 3;
String maxStr = "";
for (int l = 0; l < maxStars; l++)
{
maxStr += " ";
}

for (int i = 1; i <= segments; i++)
{
for (int line = 1; line <= height; line++)
{
String starStr = "";
for (int j = 1; j <= 2 * line + 2 * i - 3; j++)
{
starStr += "*";
}

for (int space = 0; space <= maxStars - (height + line + i); space++)
{
starStr = " " + starStr;
}
System.out.println(starStr);
}
}

for (int i = 0; i <= maxStars / 2; i++)
{
System.out.print(" ");
}

System.out.println(" " + "*" + " ");

for (int i = 0; i <= maxStars / 2; i++)
{
System.out.print(" ");
}

System.out.println(" " + "*" + " ");

for (int i = 0; i <= maxStars / 2 - 3; i++)
{
System.out.print(" ");
}

System.out.println(" " + "*******");
}
}

@java_Codings

24. Christmas tree pattern
X
X
XXX
X
XXXXX
X
XXX
XXXXXX

class ChristmasTreePattern
{
public static void main(String[] arg)
{
drawChristmasTree(4);
}

private static void drawChristmasTree(int n)
{
for (int i = 0; i < n; i++)
{
triangle(i + 1, n);
}
}

private static void triangle(int n, int max)
{
for (int i = 0; i < n; i++)
{
for (int j = 0; j < max - i - 1; j++)
{
System.out.print(" ");
}

for (int j = 0; j < i * 2 + 1; j++)
{
System.out.print("X");
}

System.out.println("");
}
}
}

@java_codings