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Coding Stories - string.Format and enum as const

Looking over some code this days I found the fallowing things.

1. Odd way of using string.Format
The fallowing code is extracted from an application:
Trace.WriteLine(string.Format("{0}{1}{2}{3}{4}{5}{6}", 
    "Generating ", 
    count, 
    " strings of size ",
    stringSize, 
    " took ", 
    duration, 
    " milliseconds."));
Trace.WriteLine(string.Format("{0}{1}{2}", 
    "Only ", 
    strings.Count, 
    " strings were generated due to uniqueness constraint."));
As we can see, ‘string.Format’ is overused. The code is not only hard to read and maintain, but the arguments are used everywhere, even when part of the string are constant. Even the spaces around words are fully missing from the format.
The above code should look something like this:
Trace.WriteLine(string.Format("Generation {0} strings of size {1} tool {2} milliseconds.", 
     count, 
     stringSize, 
     duration));
Trace.WriteLine(string.Format("Only {0} strings were generated due to uniqueness constraint.", 
     strings.Count));

2. Using ‘enum’ to manage int const
I was surprise to find this interesting way to declare const.
    public enum Constants
    {
        RandomStringSize = 2,
        Count = 500,
        KeyMaxValue = 1000,
        NumberOfReadings = 100000
    }
...
    public class FooSet
    {
        private const int count = (int)Constants.Count;
        private const int keyMaxValue = (int)Constants.KeyMaxValue;
        private const int numberOfReadings = (int)Constants.NumberOfReadings;
...
    }
    public class Car
    {
        private const int count = (int)Constants.Count;
        private const int keyMaxValue = (int)Constants.KeyMaxValue;
        private const int numberOfReadings = (int)Constants.NumberOfReadings;
...
    }
First of all why we would need to declare constants as an enum. Usually we are using enum when we have different states of possible values for a specific case. For example Color.Red, Color.Blue, Color.Black.
If we need to reuse const. in multiple location we could create a 'configuration' class that could contain this const (this class could be static). But keeping them as an enum.... hmmm.
There is a smell in the moment when we need to convert enum to int. What would happen if the const would be char or string? I don't want to imagine how you could convert it.
In this case, because the const are used in multiple classes (4 classes), without a direct connection between them, I would create a static class with this 4 const and use it directly where is needed. In this moment there is no need for mocking this value or changing them at runtime.  
    public static class RandomStringConstants
    {
        public const int RandomStringSize = 2;
        public const int Count = 500;
        public const int KeyMaxValue = 1000;
        public const int NumberOfReadings = 100000;
    }

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