Best way to get whole number part of a Decimal number
C#.NetDecimalIntC# Problem Overview
What is the best way to return the whole number part of a decimal (in c#)? (This has to work for very large numbers that may not fit into an int).
GetIntPart(343564564.4342) >> 343564564
GetIntPart(-323489.32) >> -323489
GetIntPart(324) >> 324
The purpose of this is: I am inserting into a decimal (30,4) field in the db, and want to ensure that I do not try to insert a number than is too long for the field. Determining the length of the whole number part of the decimal is part of this operation.
C# Solutions
Solution 1 - C#
By the way guys, (int)Decimal.MaxValue will overflow. You can't get the "int" part of a decimal because the decimal is too friggen big to put in the int box. Just checked... its even too big for a long (Int64).
If you want the bit of a Decimal value to the LEFT of the dot, you need to do this:
Math.Truncate(number)
and return the value as... A DECIMAL or a DOUBLE.
edit: Truncate is definitely the correct function!
Solution 2 - C#
I think System.Math.Truncate is what you're looking for.
Solution 3 - C#
Depends on what you're doing.
For instance:
//bankers' rounding - midpoint goes to nearest even
GetIntPart(2.5) >> 2
GetIntPart(5.5) >> 6
GetIntPart(-6.5) >> -6
or
//arithmetic rounding - midpoint goes away from zero
GetIntPart(2.5) >> 3
GetIntPart(5.5) >> 6
GetIntPart(-6.5) >> -7
The default is always the former, which can be a surprise but makes very good sense.
Your explicit cast will do:
int intPart = (int)343564564.5
// intPart will be 343564564
int intPart = (int)343564565.5
// intPart will be 343564566
From the way you've worded the question it sounds like this isn't what you want - you want to floor it every time.
I would do:
Math.Floor(Math.Abs(number));
Also check the size of your decimal
- they can be quite big, so you may need to use a long
.
Solution 4 - C#
You just need to cast it, as such:
int intPart = (int)343564564.4342
If you still want to use it as a decimal in later calculations, then Math.Truncate (or possibly Math.Floor if you want a certain behaviour for negative numbers) is the function you want.
Solution 5 - C#
Very easy way to separate value and its fractional part value.
double d = 3.5;
int i = (int)d;
string s = d.ToString();
s = s.Replace(i + ".", "");
s is fractional part = 5 and
i is value as integer = 3
Solution 6 - C#
I hope help you.
/// <summary>
/// Get the integer part of any decimal number passed trough a string
/// </summary>
/// <param name="decimalNumber">String passed</param>
/// <returns>teh integer part , 0 in case of error</returns>
private int GetIntPart(String decimalNumber)
{
if(!Decimal.TryParse(decimalNumber, NumberStyles.Any , new CultureInfo("en-US"), out decimal dn))
{
MessageBox.Show("String " + decimalNumber + " is not in corret format", "GetIntPart", MessageBoxButtons.OK, MessageBoxIcon.Error);
return default(int);
}
return Convert.ToInt32(Decimal.Truncate(dn));
}
Solution 7 - C#
Public Function getWholeNumber(number As Decimal) As Integer
Dim round = Math.Round(number, 0)
If round > number Then
Return round - 1
Else
Return round
End If
End Function