1.
using System;
class PyramidPattern
static void Main()
int n = 5; // Number of rows
for (int i = 1; i <= n; i++)
for (int j = i; j < n; j++)
Console.Write(" ");
for (int k = 1; k <= (2 * i - 1); k++)
Console.Write("*");
Console.WriteLine();
2.
using System;
class SeriesSum
static void Main()
Console.Write("Enter the value of x: ");
double x = Convert.ToDouble(Console.ReadLine());
Console.Write("Enter the number of terms: ");
int terms = Convert.ToInt32(Console.ReadLine());
double sum = 0.0;
int sign = 1;
for (int i = 1; i <= 2 * terms - 1; i += 2)
sum += sign * Math.Pow(x, i);
sign *= -1;
Console.WriteLine("The sum of the series is: " + sum);
Enter the value of x: 5
Enter the number of terms: 6
The sum of the series is: -46950120
3.
using System;
class DivisibleByNine
static void Main()
int start = 100;
int end = 200;
int count = 0;
int sum = 0;
Console.WriteLine("Numbers between 100 and 200 that are divisible by 9:");
for (int i = start; i <= end; i++)
if (i % 9 == 0)
Console.Write(i + " ");
count++;
sum += i;
Console.WriteLine("\n\nTotal count of numbers divisible by 9: " + count);
Console.WriteLine("Sum of numbers divisible by 9: " + sum);
Numbers between 100 and 200 that are divisible by 9:
108 117 126 135 144 153 162 171 180 189 198
Total count of numbers divisible by 9: 11
Sum of numbers divisible by 9: 1683
4.
using System;
class ArrayDifference
static void Main()
{
int[] numbers = new int[5];
// Input 5 integers from the user
Console.WriteLine("Enter 5 integers:");
for (int i = 0; i < 5; i++)
Console.Write("Enter integer " + (i + 1) + ": ");
numbers[i] = Convert.ToInt32(Console.ReadLine());
int smallest = numbers[0];
int largest = numbers[0];
// Find the smallest and largest elements
foreach (int number in numbers)
if (number < smallest)
smallest = number;
if (number > largest)
largest = number;
int difference = largest - smallest;
Console.WriteLine("The smallest element is: " + smallest);
Console.WriteLine("The largest element is: " + largest);
Console.WriteLine("The difference between the smallest and largest elements is: " + difference);
Enter 5 integers:
Enter integer 1: 6
Enter integer 2: 5
Enter integer 3: 4
Enter integer 4: 3
Enter integer 5: 8
The smallest element is: 3
The largest element is: 8
The difference between the smallest and largest elements is: 5
5.
using System;
class SortArray
static void Main()
int[] numbers = { 5, 3, 8, 1, 2 };
// Display original array
Console.WriteLine("Original array:");
foreach (int number in numbers)
Console.Write(number + " ");
Console.WriteLine();
Array.Sort(numbers);
Console.WriteLine("Array in ascending order:");
foreach (int number in numbers)
{
Console.Write(number + " ");
Console.WriteLine();
// Sort array in descending order
Array.Reverse(numbers);
Console.WriteLine("Array in descending order:");
foreach (int number in numbers)
Console.Write(number + " ");
Console.WriteLine();
6.
using System;
class ArgumentPassing
static void Main()
int val1 = 10;
int val2 = 20;
Console.WriteLine("Before call-by-value method call, val1: " + val1);
CallByValue(val1);
Console.WriteLine("After call-by-value method call, val1: " + val1);
Console.WriteLine("Before call-by-reference method call, val2: " + val2);
CallByReference(ref val2);
Console.WriteLine("After call-by-reference method call, val2: " + val2);
static void CallByValue(int value)
value = value * 2;
Console.WriteLine("Inside call-by-value method, value: " + value);
static void CallByReference(ref int value)
value = value * 2;
Console.WriteLine("Inside call-by-reference method, value: " + value);
Before call-by-value method call, val1: 10
Inside call-by-value method, value: 20
After call-by-value method call, val1: 10
Before call-by-reference method call, val2: 20
Inside call-by-reference method, value: 40
After call-by-reference method call, val2: 40
7.
using System;
class BreakContinueExample
static void Main()
Console.WriteLine("Using 'continue' to skip even numbers:");
for (int i = 1; i <= 10; i++)
if (i % 2 == 0)
continue; // Skip the current iteration if the number is even
Console.Write(i + " ");
Console.WriteLine("\n\nUsing 'break' to exit loop when a number greater than 5 is found:");
for (int i = 1; i <= 10; i++)
if (i > 5)
break; // Exit the loop if the number is greater than 5
Console.Write(i + " ");
Using 'continue' to skip even numbers:
13579
Using 'break' to exit loop when a number greater than 5 is found:
12345
8.
using System;
class FactorialTable
static void Main()
{
Console.Write("Enter the value of m: ");
int m = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Factorial Table:");
for (int i = 1; i <= m; i++)
Console.WriteLine("{0}! = {1}", i, Factorial(i));
static long Factorial(int n)
long fact = 1;
for (int i = 1; i <= n; i++)
fact *= i;
return fact;
Enter the value of m: 6
Factorial Table:
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
9.
using System;
class DiamondPattern
static void Main()
int n = 4; // Number of rows for the top half (excluding the middle row)
// Top half of the diamond
for (int i = 1; i <= n; i++)
for (int j = 1; j <= i; j++)
Console.Write("*");
Console.WriteLine();
// Bottom half of the diamond
for (int i = n; i >= 1; i--)
for (int j = 1; j <= i; j++)
Console.Write("*");
Console.WriteLine();
}
10.
using System;
class StandardDeviationCalculator
static void Main()
double[] values = { 10, 12, 23, 23, 16, 23, 21, 16 };
double mean = Mean(values);
double standardDeviation = StandardDeviation(values, mean);
Console.WriteLine("The mean is: " + mean);
Console.WriteLine("The standard deviation is: " + standardDeviation);
static double Mean(double[] values)
double sum = 0;
foreach (double value in values)
sum += value;
return sum / values.Length;
static double StandardDeviation(double[] values, double mean)
double sumOfSquares = 0;
foreach (double value in values)
{
sumOfSquares += Math.Pow(value - mean, 2);
return Math.Sqrt(sumOfSquares / values.Length);
The mean is: 18
The standard deviation is: 4.89897948556636
