We Keep Coding

return and while in function

This function accepting input and telling the user whether the input is number or not a number.
static string isnum()
{
Console.WriteLine("Write a number please");
string a = Console.ReadLine();
string nums = "123456789";
int cnt = 0;
for (int i = 0; i < a.Length; i++)
{
for (int j = 0; j < nums.Length; j++)
{
if (a[i] == nums[j])
{
cnt++;
break;
}
}
}
if (cnt == a.Length)
{
Console.WriteLine(a + " is a number");
return a;
}
else
{
Console.WriteLine(a + " is not a number");
return "";
}
}
isnum();
I would like this function to repeat herself if the input is not a number, till the input will be a number, and then to stop.
This function working now, but she's working only one time.
When I'm trying to add a while block to the function to make her run again and again till the input is number I'm getting the "not all code paths return a value" error.
is it because a "return" statement ends a function, and therefore prevent her to run again?
how can I solve that?
Thank you very much!

You can fix this with creating a loop arround it and do not return when it's not a number.
static string isnum()
{
// just loop forever.
while (true)
{
Console.WriteLine("Write a number please");
string a = Console.ReadLine();
string nums = "123456789";
int cnt = 0;
for (int i = 0; i < a.Length; i++)
{
for (int j = 0; j < nums.Length; j++)
{
if (a[i] == nums[j])
{
cnt++;
break;
}
}
}
if (cnt == a.Length)
{
Console.WriteLine(a + " is a number");
return a;
}
else
{
Console.WriteLine(a + " is not a number");
// don't return here
}
}
}

In this case the best approach is to use do while because you want your code to at least run once.
you have one problem in your code which is returning when variable is not a number. see these modifications:
static string isnum()
{
do{
Console.WriteLine("Write a number please");
string a = Console.ReadLine();
string nums = "123456789";
int cnt = 0;
for (int i = 0; i < a.Length; i++)
{
for (int j = 0; j < nums.Length; j++)
{
if (a[i] == nums[j])
{
cnt++;
break;
}
}
}
if (cnt == a.Length)
{
Console.WriteLine(a + " is a number");
return a;
}
else
{
Console.WriteLine(a + " is not a number");
}
}while(true);
}

Call it in a while loop, and loop until the result is a number:
string result = "";
while (result == "")
{
result = isnum();
}
Console.WriteLine("result is a number: " + result);

Instead of looping you can try querying the a string with a help of Linq:
using System.Linq;
...
static string isnum() {
// Keep asking user until he/she provides a number
while (true) {
Console.WriteLine("Write a number please");
string a = Console.ReadLine();
// Number is
// 1. Has at least one character
// 2. All characters of number are digits
if (a.Length > 0 && a.All(c => c >= '0' && c <= '9')) {
Console.WriteLine($"{a} is a number");
// we have a proper number, let's return int
return a;
}
Console.WriteLine($"{a} is not a number");
}
}

Inputting values for jagged array

Ok, I'm attempting to make a simple program that reads in number of pizzas sold for a given day and then have the user input the type of pizza sold for that day (with this I need to use the Split() with the user input).
I'm having issues populating the columns for my jagged array.
Now, I can get what I have to work for only 1 pizza sold, but anything beyond that it is not taking in my user input for the type of pizzas sold for that day (the column values). It's not reading in the user input as separate items so once I input, it goes to the next line like it's waiting for data instead of moving on. (Since I'm testing this for one day, it would end the program once the user input was read in).
I'm not quite sure where my issue is with my loops putting in my column values, but I'm figuring it has something with reading in the user input and placing that in the column of the jagged array. Any help would be great.
static void Main(string[] args)
{
Greeting();
string[][] pizza = new string[7][];
GetPizzas(pizza);
}
static void Greeting()
{
Write("Welcome to Z's Pizza Report!");
}
static void GetPizzas(string[][] array)
{
int numOfPizza;
string day;
for (int r = 0; r < array.Length; r++)
{
if (r == 0)
{
day = "Monday";
Write("How many total pizzas were there for {0}? ", day);
numOfPizza = int.Parse(ReadLine());
while (numOfPizza < 0)
{
Write("Number cannot be negative. Try Again: ");
numOfPizza = int.Parse(ReadLine());
}
array[r] = new string[numOfPizza];
Write("Enter all the pizzas for {0}, seperated by spaces: ", day);
for (int c = 0; c < array[r].Length; c++)
{
string total = ReadLine();
array[c] = total.Split(' ');
while (array[r] != array[c])
{
Write("Input does not match number needed. Try Again: ");
total = ReadLine();
array[c] = total.Split(' ');
}
}
}
else if (r == 1)
{
day = "Tuesday";
}
else if (r == 2)
{
day = "Wednesday";
}
else if (r == 3)
{
day = "Thursday";
}
else if (r == 4)
{
day = "Friday";
}
else if (r == 5)
{
day = "Saturday";
}
else
{
day = "Sunday";
}
}
}

The code seems overly complicated to me, but does something like this help? Oh, notice that I'm using the built-in DayOfWeek enum to parse the friendly name for the day. The difference between this and yours is that Sunday is day 0.
This line of code casts the integer to the enum, and then gets the string value:
var dayOfWeek = ((DayOfWeek)i).ToString();
I also added a helper function to get an integer from the user. It takes in a prompt string, an error string, an optional min value and an optional max value, then it prompts the user for an integer and won't return until they enter a valid value:
static int GetIntFromUser(string prompt, string error,
int minValue = int.MinValue, int maxValue = int.MaxValue)
{
int result;
if (!string.IsNullOrEmpty(prompt)) Console.Write(prompt);
while (!int.TryParse(Console.ReadLine(), out result)
|| result < minValue || result > maxValue)
{
if (!string.IsNullOrEmpty(error)) Console.Write(error);
}
return result;
}
The rest of the code looks like:
static void Main(string[] args)
{
var pizzasSold = new string[7][];
GetPizzas(pizzasSold);
for (int i = 0; i < pizzasSold.Length; i++)
{
var dayOfWeek = ((DayOfWeek)i).ToString();
Console.WriteLine("You sold {0} pizzas on {1}: {2}",
pizzasSold[i].Length, dayOfWeek, string.Join(", ", pizzasSold[i]));
}
Console.Write("\nDone!\nPress any key to exit...");
Console.ReadKey();
}
static void GetPizzas(string[][] array)
{
for (int r = 0; r < array.Length; r++)
{
var dayOfWeek = ((DayOfWeek)r).ToString();
var numPizzasSold =
GetIntFromUser($"How many total pizzas were there for {dayOfWeek}? ",
"Number cannot be negative. Try Again: ", 0);
Console.Write($"Enter all the pizzas for {dayOfWeek}, seperated by spaces: ");
var pizzasSold = Console.ReadLine().Split(new[] { ' ' },
StringSplitOptions.RemoveEmptyEntries);
while (pizzasSold.Length != numPizzasSold)
{
Console.Write($"Input does not match number needed. Try Again: ");
pizzasSold = Console.ReadLine().Split(new[] { ' ' },
StringSplitOptions.RemoveEmptyEntries);
}
array[r] = pizzasSold;
}
}

using System;
namespace ConsoleApp12
{
class Program
{
static void Main(string[] args)
{
int[][] n = new int[3][];
int i;
n[0] = new int[4];
n[1] = new int[3];
n[2] = new int[2];
// n[1] = new int[] { 1, 2, 3 };
// Console.WriteLine("enter the rollno");
for (i = 0; i < 4; i++)
{
n[0][i] = Convert.ToInt32(Console.ReadLine());
}
for (i = 0; i < 3; i++)
{
n[1][i] = Convert.ToInt32(Console.ReadLine());
}
for (i = 0; i < 2; i++)
{
n[2][i] = Convert.ToInt32(Console.ReadLine());
}
// for (i = 0; i < 3; i++)
// {
// n[i][j] = Convert.ToInt32(Console.ReadLine());
//}
for (i = 0; i <4; i++)
{
Console.Write(n[0][i] + " ");
}
Console.WriteLine();
for (i = 0; i < 3; i++)
{
Console.Write(n[1][i] + " ");
}
}
}
}

Is there a way to enter number without showing them immediately?

I want to enter 10 numbers, and then show them in 1 line like this:
1,4,5,2,456,23,... and so on..
and it keeps writing them as I am entering them, and in the end when it's supposed to show all numbers in 1 line it shows only the last one.
I know it's possible with random numbers but when I enter them on my own I don't know how not to show them at all or keep them in 1 line and if it is even possible?
int a;
int x;
Console.WriteLine("a:");
a = int.Parse(Console.ReadLine());
x = 10;
for (int i = 0; i < x; i++)
{
a = int.Parse(Console.ReadLine());
}
Console.ReadKey();

you can use
Console.ReadKey(true)
it reads a key from console and does not show it.
you can use this to read word from console without showing it
public static string ReadHiddenFromConsole()
{
var word = new StringBuilder();
while (true)
{
var i = Console.ReadKey(true);
if (i.Key == ConsoleKey.Enter)
{
Console.WriteLine();
break;
}
if (i.Key == ConsoleKey.Backspace)
{
if (word.Length > 0)
{
word.Remove(word.Length - 1, 1);
Console.Write("\b \b");
}
}
else
{
word.Append(i.KeyChar);
Console.Write("*");
}
}
return word.ToString();
}

You can use this code:
static void Main(string[] args)
{
int length = 10;
int[] myNumbers = new int[length];
for (int i = 0; i < length; i++)
{
Console.Write("Enter number:" );
myNumbers[i] = Convert.ToInt32(Console.ReadLine());
Console.Clear();
}
Console.WriteLine("Your numbers: {0}", string.Join(",", myNumbers));
}

i dont know how to write them at the end all in 1 line?
Well you need to save them as they are entered:
int num;
var nums = new List<int>();
while (nums.Count < 10)
{
Console.Write("Enter: ");
if (int.TryParse(Console.ReadLine(), out num))
{
nums.Add(num);
Console.Clear();
}
}
Console.WriteLine(string.Join(", ", nums));

C# Hangman IndexOf Loop

I am a beginner in C# and i am trying to make a "hangman" game. I got stuck at the process when the player guess a letter.
If the word for example is DATA, the application only gets the first A in DATA.
I understand that i have to loop the word to get all the A´s but i am having touble with making it work!
here is my code for the method myGuess:
public void myGuess(String letter)
{
int plats = 0;
string wordToGuess = label4.Text;
plats = wordToGuess.IndexOf(letter);
string wordToShow = label5.Text;
//ersätt "_" med bokstaven på alla positioner bokstaven dyker upp
wordToShow = wordToShow.Substring(0, wordToGuess.IndexOf(letter)) + letter +
wordToShow.Substring(plats + 1, wordToShow.Length - (plats + 1));
label5.Text = wordToShow;
}
I have been trying to google it but because i am a beginner i don't understand the
suggestions people give. Hopefully it is a way to loop for more than one letter with IndexOf?

IndexOf returns the index of the first instance of the character in the string. You could manipulate your string using substring, but you'd be making it more complicated than you need to need. Instead, you can just loop through each of the characters in the String with a for loop:
for (int i = 0; i < wordToGuess.Length; i++ )
{
if (WordToGuess[i] == letter)
{
//Update the correctly guessed letters, (using value of i to determine which letter to make visible.)
}
}
label5.Text = wordToShow;

You can use this:
label4(wordToGuess): DATA
label5(wordToShow): ****
When you call myGuess('A')
label4(wordToGuess): DATA
label5(wordToShow): *A*A
When you call myGuess('T')
label4(wordToGuess): DATA
label5(wordToShow): *ATA
...
public void myGuess(char letter)
{
string wordToGuess = label4.Text;
string wordToShow = label5.Text;
if (wordToShow.Length == 0)
{
for (int i = 0; i < wordToGuess.Length; i++)
wordToShow += "*";
}
for (int i = 0; i < wordToGuess.Length; i++)
{
if (wordToGuess[i] == letter || wordToGuess[i] == wordToShow[i])
wordToShow = wordToShow.Remove(i,1).Insert(i, Char.ToString(letter));
}
label5.Text = wordToShow;
}

Here's a long solution that's probably overly generic.
List<int> findIndexes(string myStr, char letter)
{
var foundIndexes = new List<int>();
for (int i = 0; i < myStr.Length; i++)
{
if (myStr[i] == letter)
foundIndexes.Add(i);
}
return foundIndexes;
}
string ReplaceIndex(string s, int index, char letter){
return s.Substring(0, index )
+ letter
+ s.Substring(index + 1, s.Length - (index + 1));
}
void Main()
{
string s= "data";
string wordToShow = "____";
var letter = 'a';
var indexes = findIndexes(s, letter);
foreach (var index in indexes)
{
wordToShow = ReplaceIndex(wordToShow, index, letter);
}
Console.WriteLine (wordToShow);
}

A simple for loop should handle it.
for (int i = 0; i < wordToGuess.Length; i++)
{
if (wordToGuess[i].ToString().Equals(letter.ToString(), System.StringComparison.InvariantCultureIgnoreCase))
{
wordToShow = string.Format("{0}{1}{2}", wordToShow.Substring(0, i), letter, wordToShow.Substring(i, wordToShow.Length - (i + 1)));
}
}
Here's a fiddle: http://dotnetfiddle.net/UATeVJ

Count occurences in byte list/array using another byte list/array

I am trying to get a count of all the times a byte sequences occurs in another byte sequences. It cannot however re-use a bytes if it already counted them. For example given the string
k.k.k.k.k.k. let's assume the byte sequence was k.k it would then find only 3 occurrences rather than 5 because they would be broke down like: [k.k].[k.k].[k.k]. and not like [k.[k].[k].[k].[k].k] where they over lap and essentially just shift 2 to the right.
Ideally the idea is to get an idea how a compression dictionary or run time encoding might look. so the goal would be to get
k.k.k.k.k.k. down to just 2 parts, as (k.k.k.) is the biggest and best symbol you can have.
Here is source so far:
using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using System.IO;
static class Compression
{
static int Main(string[] args)
{
List<byte> bytes = File.ReadAllBytes("ok.txt").ToList();
List<List<int>> list = new List<List<int>>();
// Starting Numbers of bytes - This can be changed manually.
int StartingNumBytes = bytes.Count;
for (int i = StartingNumBytes; i > 0; i--)
{
Console.WriteLine("i: " + i);
for (int ii = 0; ii < bytes.Count - i; ii++)
{
Console.WriteLine("ii: " + i);
// New pattern comes with refresh data.
List<byte> pattern = new List<byte>();
for (int iii = 0; iii < i; iii++)
{
pattern.Add(bytes[ii + iii]);
}
DisplayBinary(bytes, "red");
DisplayBinary(pattern, "green");
int matches = 0;
// foreach (var position in bytes.ToArray().Locate(pattern.ToArray()))
for (int position = 0; position < bytes.Count; position++) {
if (pattern.Count > (bytes.Count - position))
{
continue;
}
for (int iiii = 0; iiii < pattern.Count; iiii++)
{
if (bytes[position + iiii] != pattern[iiii])
{
//Have to use goto because C# doesn't support continue <level>
goto outer;
}
}
// If it made it this far, it has found a match.
matches++;
Console.WriteLine("Matches: " + matches + " Orig Count: " + bytes.Count + " POS: " + position);
if (matches > 1)
{
int numBytesToRemove = pattern.Count;
for (int ra = 0; ra < numBytesToRemove; ra++)
{
// Remove it at the position it was found at, once it
// deletes the first one, the list will shift left and you'll need to be here again.
bytes.RemoveAt(position);
}
DisplayBinary(bytes, "red");
Console.WriteLine(pattern.Count + " Bytes removed.");
// Since you deleted some bytes, set the position less because you will need to redo the pos.
position = position - 1;
}
outer:
continue;
}
List<int> sublist = new List<int>();
sublist.Add(matches);
sublist.Add(pattern.Count);
// Some sort of calculation to determine how good the symbol was
sublist.Add(bytes.Count-((matches * pattern.Count)-matches));
list.Add(sublist);
}
}
Display(list);
Console.Read();
return 0;
}
static void DisplayBinary(List<byte> bytes, string color="white")
{
switch(color){
case "green":
Console.ForegroundColor = ConsoleColor.Green;
break;
case "red":
Console.ForegroundColor = ConsoleColor.Red;
break;
default:
break;
}
for (int i=0; i<bytes.Count; i++)
{
if (i % 8 ==0)
Console.WriteLine();
Console.Write(GetIntBinaryString(bytes[i]) + " ");
}
Console.WriteLine();
Console.ResetColor();
}
static string GetIntBinaryString(int n)
{
char[] b = new char[8];
int pos = 7;
int i = 0;
while (i < 8)
{
if ((n & (1 << i)) != 0)
{
b[pos] = '1';
}
else
{
b[pos] = '0';
}
pos--;
i++;
}
//return new string(b).TrimStart('0');
return new string(b);
}
static void Display(List<List<int>> list)
{
//
// Display everything in the List.
//
Console.WriteLine("Elements:");
foreach (var sublist in list)
{
foreach (var value in sublist)
{
Console.Write("{0,4}", value);
}
Console.WriteLine();
}
//
// Display total count.
//
int count = 0;
foreach (var sublist in list)
{
count += sublist.Count;
}
Console.WriteLine("Count:");
Console.WriteLine(count);
}
static public int SearchBytePattern(byte[] pattern, byte[] bytes)
{
int matches = 0;
// precomputing this shaves some seconds from the loop execution
int maxloop = bytes.Length - pattern.Length;
for (int i = 0; i < maxloop; i++)
{
if (pattern[0] == bytes[i])
{
bool ismatch = true;
for (int j = 1; j < pattern.Length; j++)
{
if (bytes[i + j] != pattern[j])
{
ismatch = false;
break;
}
}
if (ismatch)
{
matches++;
i += pattern.Length - 1;
}
}
}
return matches;
}
}
Refer to the post to get the non binary of the file should be, here is the binary data:
011010110010111001101011001011100110101100101110011010110010111001101011001011100110101100101110 I am hope to have it smaller than how it started.

private static int CountOccurences(byte[] target, byte[] pattern)
{
var targetString = BitConverter.ToString(target);
var patternString = BitConverter.ToString(pattern);
return new Regex(patternString).Matches(targetString).Count;
}

With this solution you'd have access to the individual indexes that matched (while enumerating) or you could call Count() on the result to see how many matches there were:
public static IEnumerable<int> Find<T>(T[] pattern, T[] sequence, bool overlap)
{
int i = 0;
while (i < sequence.Length - pattern.Length + 1)
{
if (pattern.SequenceEqual(sequence.Skip(i).Take(pattern.Length)))
{
yield return i;
i += overlap ? 1 : pattern.Length;
}
else
{
i++;
}
}
}
Call it with overlap: false to solve your problem or overlap: true to see the overlapped matches (if you're interested.)
I have a couple of other methods with slightly different API (along with better performance) here, including one that work directly on streams of bytes.

quick and dirty with no regex. although i'm not sure if it answers the intent of the question, it should be relatively fast. i think i am going to run some timing tests against regex to see for sure the relative speeds:
private int CountOccurrences(string TestString, string TestPattern)
{
int PatternCount = 0;
int SearchIndex = 0;
if (TestPattern.Length == 0)
throw new ApplicationException("CountOccurrences: Unable to process because TestPattern has zero length.");
if (TestString.Length == 0)
return 0;
do
{
SearchIndex = TestString.IndexOf(TestPattern, SearchIndex);
if (SearchIndex >= 0)
{
++PatternCount;
SearchIndex += TestPattern.Length;
}
}
while ((SearchIndex >= 0) && (SearchIndex < TestString.Length));
return PatternCount;
}
private void btnTest_Click(object sender, EventArgs e)
{
string TestString1 = "k.k.k.k.k.k.k.k.k.k.k.k";
string TestPattern1 = "k.k";
System.Console.WriteLine(CountOccurrences(TestString1, TestPattern1).ToString()); // outputs 6
System.Console.WriteLine(CountOccurrences(TestString1 + ".k", TestPattern1).ToString()); // still 6
System.Console.WriteLine(CountOccurrences(TestString1, TestPattern1 + ".").ToString()); // only 5
}