Truncating specific decimal places without rounding in c#

While writing programs sometimes we will come across to display decimal number with specific precisions only even if we are getting decimal number with more number of precisions.



Suppose a scenario where I am getting decimal value from database or some where else like 100.456789 and i want to display this as 100.456 by truncating last 789 digits on my UI.

So here if we apply Math.Round() function for 3 decimal places then that will round decimal number like 100.457. here 7 is greater than 5 so it will add one in adjacent. If i don't want to be added that number to its adjucent then I have to go for truncate numbers.

So this can be achieved in two ways:
1. Math.Truncate function.
2. String Formatting.

1. Using Math.Truncate() function:

decimal inputNumber = 100.456789;
decimal truncatedNumber = Math.Truncate(inputNumber*1000)/100;

these line of code will give us 100.456

2. Using String Formatting:

if(inputNumber.ToString().Contain('.'))
{
     string[] inputArr =  inputNumber.ToString();

     if(inputArr.Length==2)
    {
      if(inputArr[1].Length > 3)
      {
          string output = inputNumber.ToString().Substring(0, inputNumber.ToString().LastIndexOf(".").Length + 3);

       //now here we just need to convert string number to decimal type something like below
      decimal returnValue = decimal.Parse(string.Format("{0:0.###}", output)); 

       }
    }
}


I hope this code snippet will be helpful.....