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How do I sum up every 5th number instead of all numbers?

I need some help with the for-loop. I'm trying to sum up every fifth number that I type in, instead it sums them all up. What do I have to change?
int count = 0;
double total = 0;
Console.Write("Enter your number: ");
int input = int.Parse(Console.ReadLine());
while (input != 0)
{
count++;
for (count = 0; count <= 0; count += 5)
{
total = total + input;
}
Console.Write("Enter your number: ");
input = int.Parse(Console.ReadLine());
}
Console.WriteLine("The sum of every +5 numbers is: {0}", total);
Console.ReadKey();

Assuming that you enter a list of numbers, and the 1st number and every five afterwards is added (so 1st, 6th, 11th, etc.):
int count = 0;
double total = 0;
Console.Write("Enter your number: ");
int input = int.Parse(Console.ReadLine());
while (input != 0)
{
count++;
if (count % 5 == 1)
total = total + input;
Console.Write("Enter your number: ");
input = int.Parse(Console.ReadLine());
}
Console.WriteLine("The sum of every +5 numbers is: {0}", total);
Console.ReadKey();
This works by using the modulo operator (%). The modulo operator returns the remainder of a division operation involving the number you specify.
In the code if (count % 5 == 1), the question is:
Is the remainder of count divided by 5 equal to 1?
If so, it adds the number. If not, it is skipped
The reason the remainder is one is because we want results 1, 6, 11, etc:
1 / 5 = remainder 1
6 / 5 = remainder 1
11 / 5 = remainder 1
If you change the modulo value to 0 it will return the results at position 5, 10, 15, etc.

You could just store the numbers in a list and calculate it at the end:
var numbers = new List<int>();
Console.Write("Enter your number: ");
var input = int.Parse(Console.ReadLine());
while (input != 0)
{
numbers.Add(input);
input = int.Parse(Console.ReadLine());
}
var total = numbers.Where((x, i) => (i + 1) % 5 == 0).Sum(); // i + 1 since indexes are 0-based.
Console.WriteLine("The sum of every +5 numbers is: {0}", total);

You can try this:
double total = 0;
int passover = 4;
int input = 0;
do
{
passover++;
Console.Write("Enter your number: ");
int.TryParse(Console.ReadLine(), out input);
if ( passover != 5 ) continue;
passover = 1;
total = total + input;
}
while ( input != 0 );
Console.WriteLine("The sum of every fifth numbers is: {0}", total);
Console.ReadKey();

I think the best way is to recover all the values ​​before making the sum, this code works:
double total = 0;
int input = -1;
List<int> allInput = new List<int>();
while (input != 0)
{
Console.Write("Enter your number: ");
input = int.Parse(Console.ReadLine());
allInput.Add(input);
}
for (int i = 0; i < allInput.Count()-1; i += 5)
{
total = total + allInput[i];
}
Console.WriteLine("The sum of every +5 numbers is: {0}", total);
Console.ReadKey();

Your sample would go forever, because there is no break point in your loop. You should always put a break point in your loop, otherwise it'll loop indefinitely.
Here is what you need :
int total = 0;
int count = 0;
Console.Write("Enter your number: ");
while (true)
{
int input = 0;
bool isNumber = int.TryParse(Console.ReadLine(), out input);
if (isNumber)
{
count++;
if (count % 5 == 0)
total += input;
}
else
{
break;
}
Console.Write("Add another number or press enter to get the sum : ");
}
Console.WriteLine("The sum of every +5 numbers is: {0}", total);
Console.ReadKey();
So, you'll need first to put the user input inside a loop, and keep asking the user for adding another number until hits the condition where you close this loop. In the example, I decided to break the loop if the user typed anything not a number. but I told the user to press enter to get the some, to end the loop. For you, you'll need to translate that to your application breakpoint, how would you want the user to get the sum ?. Then, change the condition to your logic, so it breaks the loop and gets the sum.
another point is that int.TryParse. When you want to convert strings to numbers (int, long, decimal ..etc). You should always use `TryParse, this will verify the number, if the conversion failed, it'll return false. This way you can maintain the conversion and do something about it.

How do I create a C# program that asks for a value between 1 and 100 that uses a loop

so I am trying to create a C# program that asks for a value between 1 and 100 that uses a loop to determine the sum of all values between 1 and the entered value and if the number entered in is less than one or more than 100 it prints out "Sorry. Try again." I've been working on this for days but I can't get it to print the sum, I keep getting 0 and whenever I test it and enter a number under one or over 100, it won't print the error message I want. Here is the code:
using System;
namespace PrintSumL
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter a beginning value between 1 and 100");
int s = Convert.ToInt32(Console.ReadLine());
int sum = 0;
Console.WriteLine("Sum of values: " + sum);
Console.ReadKey();
Random rand = new Random();
rand.Next(1, 51);
while (0 < s && s < 101)
{
sum += s;
s++;
if (s < 0 && 101 < s)
{
Console.WriteLine("Invalid input. Try again.");
}
{
}
{
}
}
}
}
}

You can think of the program as executing line by line from top to bottom, and only moving back up when it reaches the end of the while loop. The end of the while loop is the } that matches the { at the start of the loop.
Knowing that, you can see why it always says sum is zero. From your code:
int sum = 0;
Console.WriteLine("Sum of values: " + sum);
Since the program executes "line by line from top to bottom", it will first set sum to 0, and then print sum out. So it will always print "Sum of values: 0". If you want it to print out the sum after it has calculated it, then you need to move the WriteLine down below where the sum is calculated.
The same issue applies to the "Invalid input. Try again.": the line that prints this statement appears after while (0 < s && s < 101), so will only execute if s is between 0 and 101. Since you're trying to catch the scenario where s is not between 0 and 101, you'll need to move the statement to above the while loop.
So, to fix your immediate problems, just do two things:
1) move the two lines
Console.WriteLine("Sum of values: " + sum);
Console.ReadKey();
to after the while loop (just after the } which is at the same level of indentation as while).
2) move the three lines
if (s < 0 && 101 < s)
{
Console.WriteLine("Invalid input. Try again.");
}
up to just below int s = Convert.ToInt32(Console.ReadLine());, and then double check the logic. It sounds like you want to print the statement if s is less than zero or s is greater than 101.

if loops are a requirement you should follow Heath Raftery instruction
else you could write something like:
static void Main(string[] args)
{
Console.WriteLine("Enter a beginning value between 1 and 100");
int s = Convert.ToInt32(Console.ReadLine());
if (s < 0 || s > 100)
Console.WriteLine("Invalid input. Try again.");
else
Console.WriteLine($"Sum of values: {Enumerable.Range(1,s).Sum()}");
}
or as haldo commented you could just use the formula of N * (N+1) / 2 and replace the last WriteLine with:
Console.WriteLine($"Sum of values: {s * (s+1) / 2}")

Try this:
static void Main(string[] args)
{
while (true)
{
Console.Write("Enter a number between 1 and 100: ");
int Number = Convert.ToInt32(Console.ReadLine());
if (Number < 0 || Number > 100)
Console.WriteLine("Sorry. Try again.");
else
{
int sum = 0;
for (int i = 1; i <= Number; i++)
{
sum = sum + i;
}
Console.WriteLine("Sum of values: " + sum);
}
}
}

Here is an algorithm that works...
Console.WriteLine("Enter a value between 1 and 100");
var input = int.Parse(Console.ReadLine());
int sum = 0;
if (input<1 || input>100) {
Console.WriteLine("Sorry, Try again");
}
else{
while(input > 2){
input-=1;
sum+=input;
}
}
Console.WriteLine("Sum of values: " + sum);

C# programming-code for sum of digits and reverse number

I wrote a code to find the sum of the digits and the reverse of a number-
static void Main(string[] args)
{
int number, sum = 0;
Console.WriteLine("Enter a number:");
number = int.Parse(Console.ReadLine());
while (number!= 0)
{
int m = number % 10;
number = number / 10;
sum = sum + m;
}
Console.WriteLine("Sum of digits of the number:" + sum);
Console.ReadLine();
int reverse = 0;
while (number!= 0)
{
reverse = reverse * 10;
reverse = reverse + number % 10;
number = number / 10;
}
Console.WriteLine("Reversed Number is:" + reverse);
Console.ReadLine();
}
but, the output for reversed number comes as 0. I checked my code, and I am not sure what is wrong with it.

You modify number as you sum the digits so when you try to go through the second loop, number is already at 0. Save off the input and reset number before the second loop:
Console.WriteLine("Enter a number:");
int input = int.Parse(Console.ReadLine());
number = input;
while (number!= 0)
{
// ...
}
Console.WriteLine("Sum of digits of the number:" + sum);
number = input; // reset number back to original input
// ...

There's also a possible solution to the problem using LINQ:
int number = 1234567890;
int sumOfDigits = number.ToString().Select(c => int.Parse(c.ToString())).Sum();
int reversedNumber = int.Parse(new string(number.ToString().Reverse().ToArray()));
Console.WriteLine($"sum of digits: {sumOfDigits}");
Console.WriteLine($"reversed number: {reversedNumber}");

Print random numbers in a range

I have got this homework assignment and I have come with a solution which works, but I do not understand why when entering range from [0 to 1] the Random() function prints only zeroes. When I ad 1 to the max argument it works //rnd.Next(min, max + 1);, but why only zeroes when it is left like this: rnd.Next(min, max);
static void Main()
{
Console.Write("Please enter integer n: ");
int n = int.Parse(Console.ReadLine());
Console.Write("Please enter min integer: ");
int min = int.Parse(Console.ReadLine());
Console.Write("Please enter max integer: ");
int max = int.Parse(Console.ReadLine());
Random rnd = new Random();
for (int i = 0; i <= n; i++)
{
Console.WriteLine(rnd.Next(min, max+1));
}
}

Random.Next produces a number in the range [min, max) -- that means min is a possible result, but max is not. The only integer in the range [0, 1) is 0.

It is part of the language definition.
The maximum value is exclusive, not inclusive, so if you want max to be included, you must add 1 to it.

C# - displaying the max, min, and average

I am new to C#. I have been working on this program and researching but am not getting anywhere. The goal is to have the user enter numbers (how many is up to the user). when they enter a 0, it will stop the program and display the minimum number entered, the maximum number entered, and the average of all numbers entered. I am not getting any errors and I am getting. If someone can please point me in the right direction.
The WriteLines are returning:
Lowest number is 0
Highest number is 0
Average is: 0
Count: 5
Here is my code:
int LOWEST =0;
int HIGHEST=0;
const int STOP = 0;
double average = 0;
int input;
int count = 0;
Console.WriteLine("Enter a number. You can end the program at anytime by entering 0");
input = Convert.ToInt32(Console.ReadLine());
while (input != STOP)
{
for (int i=0; input != STOP; i++)
{
Console.WriteLine("Enter a number. You can end the program at anytime by entering 0");
input = Convert.ToInt32(Console.ReadLine());
count++;
var Out = new int[] { input };
LOWEST = Out.Min();
HIGHEST = Out.Max();
average = Out.Average();
if ((input > LOWEST) || (input < HIGHEST))
{
LOWEST = Out.Min();
}
if (input > HIGHEST)
{
HIGHEST = Out.Max();
}
}
}
Console.WriteLine("Lowest number is {0}", LOWEST);
Console.WriteLine("Highest number is {0}", HIGHEST);
Console.WriteLine("Average is {0}", average);
Console.WriteLine("Count: {0}", count);
Console.ReadLine();

On each run you are constructing a new array of integers:
var Out = new int[] { input };
After this line, Out contains one item: the last input. Calling Min, Max and Average on it will return the last value. Which is zero if you ended the program.
instead of creating a new array each time, you want to create a List<int> at the beginning of your program and then add each input to it. You can then use the whole list of values to calculate Min, Max and Average.
Eventually you can change your code into something like this:
const int STOP = 0;
int input = -1;
List<int> Out = new List<int>();
while (input != STOP)
{
Console.WriteLine("Enter a number. You can end the program at anytime by entering 0");
input = Convert.ToInt32(Console.ReadLine());
if (input == STOP) break;
Out.Add(input);
}
Console.WriteLine("Lowest number is {0}", Out.Min());
Console.WriteLine("Highest number is {0}", Out.Max());
Console.WriteLine("Average is {0}", Out.Average());
Console.WriteLine("Count: {0}", Out.Count);
Console.ReadLine();

List<int> numbers = new List<int>();
numbers.Add(10);
numbers.Add(30);
numbers.Add(20);
numbers.Add(0);
numbers.Max();
numbers.Min();
numbers.Average();
returns 30, 0 and 15.

Before your loop, you should probably make Out an extensible data structure analogous to an array, the List.
List<int> Out = new List<int>();
then each loop, you can
Out.Add(input);
Since this sounds like an exercise for the reader, you can then traverse your list and compute the average from all data values.
Alternately, before the loop, you could declare
int n = 0;
int total = 0;
and each loop, do
n += 1;
total += input;
From these, you should be easily able to compute the average.