C# how to find how many zero after dot in number format

Question

this is a number format in excel stored in string variable like

var format="####0.0%;(####0.0%);####0.0%";

we can see there is one zero after dot but there could be 3 or more zero. so how to write code which will extract how many zeros are there after dot in number format. if possible help me with sample code. thanks

Answer 1

I have done the job this way.

public static int DigitCount(string input, char matchChar = '0')
        {
            int count = 0;
            int firstpost = 0;
            int lastpos = 0;
            string actualtext = "";
            //string input = "####0.00%;(####0.0%);####0.0%";

            firstpost = input.IndexOf(".") + 1;
            lastpos = input.IndexOf(";");
            actualtext = input.Substring(firstpost, lastpos - firstpost);
            count = actualtext.Count(x => x == matchChar);

            return count;
        }

Answer 2

The following code is done for reusability, otherwise the code in Helpers.GetZeros can be placed in a button click for instance.

Container for results

public class Container  
{  
    public int Index { get; set; }  
    public string Value { get; set; }  
    public int Length { get; set; }  
}  

Work code

public class Helpers  
{  
    public static List<Container> GetZeros(string format)  
    {  
        List<Container> list = new List<Container>();  
        Regex regex = new Regex(@"\d+(\.\d+)?");  
        var matches = regex.Matches(format);  
        int index = 0;  
        foreach (Match match in matches)  
        {  
            var length = match.Value.Replace("0.", "").Length;  
            list.Add(new Container() {Index = index, Value = match.Value, Length = length});  
            index++;  
        }  
  
        return list;  
    }  
}  

Use it

private void GetZerosButton_Click(object sender, EventArgs e)  
{  
  
    List<Container> list = Helpers.GetZeros("####0.0%;(####0.00%);####0.0000%");  
  
    Debug.WriteLine("Index     Length    Value ");  
    foreach (var container in list)  
    {  
        Debug.WriteLine($"{container.Index,-10}{container.Length, -10}{container.Value}");  
    }  
}