Getting what is after the Decimal place, in any number

Getting what is after the Decimal place, in any number

• mandokev

  okay, i have managed to make a method
  
  

  private double NumberDecimalParser ( double number ) { double result= 0.0; string TempStr = number.ToString (); char[] Delim = { '.' }; string[] TempStrArry = TempStr.Split (Delim[0]); if (TempStr!="0") { TempStr = "0." + TempStrArry[1].ToString (); } try { result = Convert.ToDouble ( TempStr ); } catch (Exception e) { MessageBox.Show ( e.ToString () ); } return result; }

  
  
  
  but i see your way, and i dont understand this bit
  
  double subnum = pi - (int)pi;   // Subtract it from the whole number
  
  What does (int)pi do why the brackets before pi why not after it or why not int (pi) can you explain to me, this is new to me as i am beginning C# programming
  
  
  

• DRK12345

  I Try to use Math.IEEERemainder - it should do what you want, and % is only for integer values, if I'm not mistaken (I'm a VB-guy, and I don't know C# very well).
  
  And about "number - (int)number". What does it do
  
  You number is, e.g. 123.456. When it's converted to System.Int32 by (int) casting, only integer part is left (that is 123). And 123.456 - 123 is exactly what you need. You know, in the school they define the decimal part of the number as the difference between itself and its integer part.
  
  
  

• xudeutsch

  Avada Kedavra wrote:

  yeah that helps alot, but why did we not use the Modulus % to get the remainder i mean would mod (%) give me this too 23423.2342/131.12 = number.decimals if i used the mod (%) would it give me the decimals

  
  
  Hi,

  The modulus operator having the symbol percent (%) is used to get the remainder of a division; we cannot use that operator to truncate a floting point number into whole number.

  In addition to casting double to get the integer part of a double number, you could also use the Math.Truncate method:

  double pi = Math.PI;
  double piInt = Math.Truncate(pi);

  double subnum = pi - piInt;
  
  Using the above procedure, we can rewrite the NumberDecimalParser like this:

  private double NumberDecimalParser(double input) {   double truncatedInput = Math.Truncate(input);   double result = input - truncatedInput;   // This will extract only the numbers after   // the decimal places into a string   string subnumInString = result.ToString();   int decimalLocation = subnumInString.IndexOf('.') + 1;   if (decimalLocation > 1)   {     subnumInString = subnumInString.Remove(0, decimalLocation);   }   return double.Parse(subnumInString); }

  
  
  Best Regards,

  -chris
  

  
  
  

• Tamar

  yeah that helps alot,
  but why did we not use the Modulus % to get the remainder
  i mean would mod (%) give me this too
  
  23423.2342/131.12 = number.decimals
  
  if i used the mod (%) would it give me the decimals
  
  
  

• SHG

  Hi,
  
  You can get the subnumber of a float by subtracting it from its whole number:
  
  double pi = 3.1415926;           // This is your number
  double subnum = pi - (int)pi;   // Subtract it from the whole number
  
  The result stored in subnum variable is 0.1415926, all you left to do now is a process to remove "0." from the begining of your number.
  
  Regards,
  
  -chris
  
  

• skcheng

  Hello World,
  
  I don't know if I am overstepping my bounds, but there is a great feature in VS2K5 that allows people (like me) to play with the language: the Immediate window.  To best understand the ways rudimentary functions behave start a program that only runs a breakpoint.  Once the program stops, open the immediate window and start typing your code away.  If you desire to see how a specific function works, use it many times in many different ways.  That was how I obtained a grasp of these math functions (actually I used MatLab, but math functions are the same in any language).  Also, if you are doing any heavy math stuff and don't want to write a library of math features, MathNet on sourceforge is a great program.
  
  Benfield
  

• danb2005

  Avada Kedavra wrote:

  okay, i have managed to make a method but i see your way, and i dont understand this bit double subnum = pi - (int)pi;   // Subtract it from the whole number What does (int)pi do why the brackets before pi why not after it or why not int (pi) can you explain to me, this is new to me as i am beginning C# programming

  
  
  Hi,
  
  I used direct casting to cast variable from type double to integer, this it done this way:
  
  (int)pi;  // The (int) means I'm casting the variable pi to type int.
  
  You can also use the convert class in place of direct casting, to make the code easier to read:
  
  Convert.ToInt32(pi);  // Same as the above
  
  Both of the two methods, direct casting or by using the Convert class, is to cast the double to integer in order to remove the decimal places:
  
  (int)pi; // returns 3
  Convert.ToInt32(pi);
  
  The subtraction looks like this:
  
  double subnum = 3.1415926 - 3;  // This returns 0.1415926
  
  
  Hope this helps,
  
  -chris
  
  

• Saravana

  Second thing, what is the use of % then woudnt it give us the remaining of a division too like double subnum = pi - (int)pi;   // Subtract it from the whole number or no
  
  Please explain to me the () thingy thanks :)
  
  
• Getting what is after the Decimal place, in any number