C＃如何将double转换为int数组

Question

This is my first post on Stack Overflow ever. If I do it wrong, please correct me:

Using C#, I'd like to convert a double to an int array of variable length equal to the total number of digits in the double.

for example, if I had the number 35.777778, I would want to convert it an int array where

array[0] = 3
array[1] = 5
array[2] = 7
etc.

I plan to iterate through the array and compare array[i] to array[i + 1].

The double will be the quotient of two variable numbers. So it may have very few digtis or a lot of digits.

So far I have tried to convert it to a string and then to an array of ints. But it crashes at the decimal point.

Please help me...

Answer 1

This should do it:

int[] array = 35.777778.ToString().Replace(".", String.Empty)
                                  .Select(c => (int)Char.GetNumericValue(c))
                                  .ToArray();

Answer 2

You could do it the way you were doing (convert to string and then parse each char to an int) and just strip out the decimal point. Like so:

var nums = decimalNum.ToString().Replace('.', '').ToCharArray();
int[] numbers = new int[nums.Count];
var x = 0;
foreach (var item in nums)
{
    numbers[x] = Integer.ParseInt(item);
    x++;
}

This obviously isn't the prettiest solution, but it would work.

Answer 3

Floating point to decimal digit conversion is a hard problem. In .NET, the tool have available is really the double.ToString method which is bloated and especially bad when you want the digits. As you see the other answers all have to parse back to integer.

If performance is important there are good double to string conversion algorithms out there that can be modified to fit your needs. This one is good:

C# port of google's Grisu conversion

Answer 4

int[] array = 35.777778.ToString().Where(c => char.IsDigit(c)).Select(c1 => Convert.ToInt32(c1.ToString())).ToArray();

即使double值包含任何字符（例如E-10），此代码也将起作用