I'm trying to calculate the number of digit before the floating points. for example
input: 123.4
expected output: 3
my actual output: 5
I'm sure there is something wrong with the digit.equals(".") since the program does not break out of the loop.
this is my code:
public class Program
{
public static void Main()
{
Console.WriteLine(HowManyDigit(123.4));
}
public static Int32 HowManyDigit(Double number)
{
string x = number.ToString();
var counter = 0;
for (int i = 0; i < x.Length; i++)
{
var digit = x[i];
//Console.WriteLine(counter);
if (digit.Equals("."))
{
break;
}
else
{
counter++;
}
}
return counter;
}
}
The reason your code does not work breaks down to this logic:
var digit = x[i];
if (digit.Equals("."))
{
break;
}
The char digit will never be equal to the string "."
If you change your code to:
//Note that I use a char, indicated by ''
if (x[i].Equals('.'))
{
break;
}
Or simply:
if (x[i] == '.')
{
break;
}
Either of those two methods will give you a drastically different result from your current code.
That being said, this method is not really the best way of doing what you want. You can simply use IndexOf() to get the exact number you want:
public static int HowManyDigit(double number)
{
return number.ToString().IndexOf('.');
}
Fiddle here
Just compute the logarithm of base 10 and then convert to integer with floor.
n = Math.Floor(Math.Log10(x))+1;
Try this x.IndexOf('.') this will be your answer
Replace this:
if (digit.Equals("."))
With this:
if (digit.Equals('.'))
Now your output should be 3.
Here is a LINQ solution:
double number = 123.4;
var result = number.ToString().TakeWhile(x => char.IsDigit(x)).Count();
Related
when I enter 1 for n
and 1111 for lines
the sum must be 1+1+1+1=4 but the output is 1.
THIS IS THE QUESTION...
you will get a (n) then (n) lines as an input, In each line there are some numbers (we don’t know how many they are) and you must print (n) lines, In the i-th line print the sum of numbers in the i-th line.
using System;
namespace prom2
{
class Program
{
static void Main(string[] args)
{
int lines=0, sum = 0;
Console.Write("Enter a number of lines ");
int n = int.Parse(Console.ReadLine());
for (int i = 1; i <= n&n>0&1000>n; i++)
{
Console.WriteLine("Enter line " + i + " numbers");
lines = int.Parse(Console.ReadLine());
lines = lines / 10;
sum += lines % 10;
Console.WriteLine("sum is " + sum);
}
}
}
}
Try this:
static void Main(string[] args)
{
int input;
bool times = true;
List<int> numbers = new List<int>();
while (times)
{
Console.Clear();
Console.WriteLine("Enter number: ");
var num = int.TryParse(Console.ReadLine(), out input);//tryparse will output a bool into num and set input to a int
if (num)
{
numbers.Add(input);//only integers will be added to list
}
Console.Clear();
Console.WriteLine("Another? Y or N");//ask if they want to sum more numbers
var yesno = Console.ReadLine();//get answer from user
if (yesno.ToUpper().Trim() != "Y")//if N or anything else
{
//assume no
times = false;
}
Console.Clear();
}
var sum = numbers.Sum();
Console.WriteLine("Sum : " + sum.ToString());
Console.ReadLine();//just to pause screen
}
Because Console.ReadLine returns a string, and it's possible to treat a string as if it's an array of chars (where char represents a single character), you can have a method like this to calculate the sum of all the digits in a single line:
private int SumTheDigits(string line)
{
var sum = 0;
foreach (var character in line)
{
sum += int.Parse(character.ToString());
}
return sum;
}
Please note this method contains no validation - ideally you should validate that line is purely numeric, otherwise int.Parse will throw an exception, although the same is true of the code you provided too.
If you want to work with multiple lines of console input, just call this method from within another loop which solicits / works through those lines of console input.
Edit
My answer doesn't answer all of your question, it only answers the part which asks how to calculate the sum of the digits in a numeric string, and it does work, to the extent that it correctly does what it says on the tin.
Here's all the code I wrote to validate the answer before posting the original answer (I wrote it as a xUnit unit test rather than a console application, but that doesn't change the fact that the code I shared works):
using System;
using Xunit;
namespace StackOverflow71442136SumDigits
{
public class UnitTest1
{
[Theory]
[InlineData("1", 1)]
[InlineData("12", 3)]
[InlineData("23", 5)]
[InlineData("1234", 10)]
[InlineData("123456789", 45)]
public void Test1(string line, int expectedSum)
{
var actualSum = this.SumTheDigits(line);
Assert.Equal(expectedSum, actualSum);
}
private int SumTheDigits(string line)
{
var sum = 0;
foreach (var character in line)
{
sum += int.Parse(character.ToString());
}
return sum;
}
}
}
You might want to read How do I ask and answer homework questions?
I have a large float that I want to convert into a string with commas without rounding.
Here is what I have:
String.Format("{0:#,###}", val);
This turns 17154177 into 17,154,180
I would like to keep the commas but not round at the end using c#.
This may be what you're looking for
using System;
class MainClass {
public static void Main (string[] args) {
float original = 17154177;
// 1. Convert the number to a string
string value = original.ToString("R");
// 2. Reverse the string
string reversed = Reverse(value);
// 3. Add the comma on each third number, backwards
string formatted = "";
for(int i = 0; i < reversed.Length; i++) {
if ((i+1) % 3 == 0) {
formatted += reversed[i] + ",";
} else {
formatted += reversed[i];
}
}
// 4. Reverse it back to the original order
formatted = Reverse(formatted);
Console.WriteLine (formatted);
}
/* Reverses a string */
public static string Reverse(string text)
{
char[] cArray = text.ToCharArray();
string reverse = String.Empty;
for (int i = cArray.Length - 1; i > -1; i--)
{
reverse += cArray[i];
}
return reverse;
}
}
I got the reverse method from this question.
Change your data type to decimal (28-29 significant digits) to have higher precision compared to float (7 digits).
Or you can change it to var. It will let the compiler figure out the best data type to use.
var number = 17154177;
Console.WriteLine(String.Format("{0:#,###}", number));
See this fiddler link, working code
This question already has answers here:
Evaluating string "3*(4+2)" yield int 18 [duplicate]
(13 answers)
Closed 3 years ago.
I created a console application that will take user input of any number and + or - operator for now, and returns the result.
for example user can input 1+2+3+4, and result should be 10.
My problem is that I cannot figure out how to get the last number to be summed into the total result.
that mean in my code only 1+2+3 will be calculated while 4 will be ignored.
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
namespace SimpleCalculator
{
public class Program
{
public static void Main()
{
int result = 0;
int number;
string numberString = "";
Console.WriteLine("Enter numbers followed by operation eg. x+y-z");
while (true)
{
string userInput = UserInput();
//Loop into each element of the input string
for (int i = 0; i < userInput.Length; i++)
{
if((IsNumber(userInput[i])))
{
numberString += userInput[i];
}
else if (!IsNumber(userInput[i]))
{
number = Int32.Parse(numberString);
numberString = "";
result = PerformCalculation(result, number, userInput[i]);
}
}
number = Int32.Parse(numberString);
result += number;
Console.WriteLine($"{userInput}={result}");
}
}
// check if input is number or operator
static bool IsNumber(char input)
{
if (char.IsDigit(input)){return true;}
else{return false;}
}
static string UserInput()
{
string User_input = Console.ReadLine();
return User_input;
}
static int PerformCalculation(int sum, int num, char op)
{
switch (op)
{
case '+': return sum + num;
case '-': return sum - num;
default: throw new ArgumentException("Uknown operator");
}
}
}
}
You have already figured out that you are not adding the last number and lets do some thinking to figure out why.
The number will only be added when you call PerformCalculation and whats the condition that this will be called? else if (!IsNumber(userInput[i]))
If you look at your input do you see a non number at the end of the string? if not then PerformCalculation wont get called.
How do you fix that? Before you return the result check if numberString is empty, if not then do the final calculation before returning the result.
Since this is a homework problem i will leave the rest as an exercise.
I've been working on an assignment and I'm a beginner to C#. I have to implement a program that's similar to what BigInt can do: perform addition, subtraction, or multiplication with two absurdly large values (without actually using the BigInt library). I was told to use CompareTo and that it would make creating the add, subtract, and multiply methods easy, but I have no clue how to implement CompareTo. I don't even know if my class is implemented correctly or if I am missing something important.
Here is my code:
public class HugeInt
{
char sign;
public IList<int> theInt = new List<int>();
public string ToString(IList<int> theInt)
{
string bigInt = theInt.ToString();
return bigInt;
}
public HugeInt CompareTo(HugeInt num1)
{
int numParse;
string number = ToString(theInt); /// I did this to convert the List into a string
for(int i = 0; i < number.Length; i++)
{
bool temp = Int32.TryParse(number, out numParse); /// Supposed to change each index of the string to a separate integer (not sure how to properly do this)
/// These are *supposed to* perform operations on two HugeInts ///
num1.plus(numParse, num1);
num1.minus(numParse, num1);
num1.times(numParse, num1);
}
return num1;
}
I'm not here to ask for all the answers for this assignment, I've just been working on this for hours now and can't figure out what I'm doing wrong -- I have already done a lot of google searching. Thanks in advance for all advice and help!
To write such a class, it requires you know a little bit about how to do math by hand. For example, when adding two numbers, you start by adding their least significant digits. If the result is greater than 9, you have to carry a 1 to the next digit (explanation). Then you continue to the next digit.
Now, here is my take on it. I want to save the "huge int" as a list of digits starting from the least significant digit. Then I implement the Plus method as described above. I can compare two "huge ints" by looking at the number of digits. The number with the most digits is the largest. In the case the number of digits are the same, I will need to compare each digit one-by-one, starting from the most significant digit.
The below is just something to get you started. It only handles positive integers and has Plus and CompareTo methods. Be aware there are plenty of corner cases that I have not taken care of.
It can be used like this:
var num1 = new HugeInt("11112222333399998888777123123");
var num2 = new HugeInt("00194257297549");
Console.WriteLine(num1.Plus(num2).ToString()); // Writes 11112222333399999083034420672
Console.WriteLine(num1.CompareTo(num2)); // Writes -1 since num1 > num2
Here is the class:
public class HugeInt
{
// The array that contains all the digits of the number. To create a new number, you do not change this array but instead you create a new instance of HugeInt.
// The first digit is the least significant digit.
private readonly int[] digits;
public HugeInt(string number)
{
// Trim off the leading zeros
number = number.TrimStart('0');
if (number == "")
number = "0";
// Convert to digit array with the least significant digit first
digits = number.ToCharArray().Select(c => int.Parse(c.ToString())).Reverse().ToArray();
}
public HugeInt(IList<int> digits)
{
// Trim off the leading zeros
var d = digits.ToList();
while (d.Count > 1 && d.Last() == 0)
d.RemoveAt(d.Count - 1);
// Convert to digit array with the least significant digit first
this.digits = d.ToArray();
}
public HugeInt Plus(HugeInt num)
{
// Add two positive integers by adding each digit together, starting with the least significant digit.
var result = new List<int>();
int carry = 0;
for (var i = 0; i < this.digits.Length || i < num.digits.Length; i++)
{
var digit1 = i < this.digits.Length ? this.digits[i] : 0;
var digit2 = i < num.digits.Length ? num.digits[i] : 0;
var digitResult = digit1 + digit2 + carry;
carry = 0;
if (digitResult >= 10)
{
digitResult -= 10;
carry = 1;
}
result.Add(digitResult);
}
if (carry > 0)
result.Add(carry);
return new HugeInt(result);
}
public int CompareTo(HugeInt num)
{
// First compare by length of number
if (this.digits.Length > num.digits.Length)
return -1;
else if (this.digits.Length < num.digits.Length)
return 1;
else
{
// If lengths are equal, then compare each digit - starting with the most significant digit.
for (var i = this.digits.Length - 1; i >= 0; i--)
{
var cmp = this.digits[i].CompareTo(num.digits[i]);
if (cmp != 0)
return cmp;
}
return 0;
}
}
public override string ToString()
{
return String.Join("", digits.Reverse());
}
}
Is there a way to format a double number that always have n digits sepecified by user?
For example if user want to see always 4 digits, take the following numbers as example:
Original Formatted
------- ---------
3.42421 3.424
265.6250 265.6
812.50 812.5
12.68798 12.68
0.68787 0.687
I made up this but it just allows for number of floating points! it is not what I wanted!
public string ToEngV(double d, int percision = 0)
{
string zeros = string.Empty;
if (percision <= 0)
{
zeros += "0";
}
else if (percision > 0)
{
for (int i = 0; i < percision; i++)
{
zeros += "0";
}
}
return String.Format("{0:0." + zeros + "}", d)
}
Imagine I call the above method for a number like 812.50 and I set the precision to (this is now used for all numbers I am going to format). Obviously the output will be 812.5
But if I give the another number like 1.61826 I will get 1.6 and this ruins the formatting in the page I show these number to users. I need that to be 1.618
Thus I want my method to always show N digit!
I'm not sure if your asking to round or truncate numbers, so I wrote this method:
public static string ToEngV(this double d, int digits, bool round)
{
var lenght = Math.Truncate(d).ToString().Length;
if (lenght > digits)
{
throw new ArgumentException("...");
}
int decimals = digits - lenght;
if (round)
{
return Math.Round(d, decimals).ToString();
}
else
{
int pow = (int)Math.Pow(10, decimals);
return (Math.Truncate(d * pow) / pow).ToString();
}
}
Example:
var numbers = new double[] { 3.42421, 265.6250, 812.50, 12.68798, 0.68787 };
foreach (var number in numbers)
{
Console.WriteLine(number.ToEngV(4, false));
}
Console.WriteLine()
foreach (var number in numbers)
{
Console.WriteLine(number.ToEngV(4, true));
}
Output:
3.424
265.6
812.5
12.68
0.687
3.424
265.6
812.5
12.69
0.688
Note that if your number has more integer digits than digits you will get an ArgumentException.
number.ToString("#0.000").Substring(0, 5);
I'm not sure this is what you're searching for, anyway give it a try:
string FmtDbl(double num, int digits)
{
digits++; // To include decimal separator
string ret = num.ToString();
if (ret.Length > digits) return ret.Substring(0, digits);
else return ret + new String('0', digits - ret.Length);
}
Note that if your number has more than digits integer digits, this doesn't work...
What about something like:
d.ToString().PadRigth(4,'0').SubString(0,4);
public static void RunSnippet()
{
Console.WriteLine(myCustomFormatter(3.42421));
Console.WriteLine(myCustomFormatter(265.6250));
Console.WriteLine(myCustomFormatter(812.50));
Console.WriteLine(myCustomFormatter(12.68798));
Console.WriteLine(myCustomFormatter(0.68787));
Console.ReadLine();
}
public static double myCustomFormatter(double value)
{
string sValue = value.ToString();
string sFormattedValue = sValue.Substring(0,5);
double dFormattedValue= Convert.ToDouble(sFormattedValue);
return dFormattedValue;
}