根据 C# 中包含的字符为字符串赋值的简单方法是什么？

Question

I'm trying to get a sum value based on what characters a string contains. The character values are determined by me and are somewhat arbitrary ('A' = 1, 'B' = 4, 'C' = 2, etc.). For example, if string s = "ABC" then int value = 7 because 1 + 4 + 2 = 7. What would be an efficient way to write this in C#?

Right now my code looks like this:

//Declare variables
string name = JOHN
int i = 0;
int nameValue = 0;
string temp = "";
string[] nameArray;

//Convert name to string array so I can use String.Contains() to check what letters are in name
foreach (char c in name)
{
   temp += c.ToString();
   temp += ".";
}

temp = temp.Remove(temp.Length - 1, 1);
nameArray = temp.Split('.');            

//Determine nameValue by iterating through nameArray and checking each string
foreach (string s in nameArray)
{
   if (nameArray[i].Contains('A')) { nameValue += 1 }
   else if (nameArray[i].Contains('B')) { nameValue += 4 }
   else if (nameArray[i].Contains('C')) { nameValue += 2 }
   else if (nameArray[i].Contains('D')) { nameValue += 3 }
   .
   .
   .
   else if (nameArray[i].Contains('Y')) { nameValue += 7 }
   else if (nameArray[i].Contains('Z')) { nameValue += 5 }

   i++;
}

Console.WriteLine(nameValue);

I changed the string to a string array because I have names that have repeating letters (ie Jill), and I want to give every letter in the name a value. If I used String.Contains() without separating every letter, it would only count repeating letters once, I think.

I feel like there has to be a better way than doing all that string manipulation and using a separate conditional statement for every letter in the alphabet, but I couldn't find anything. Thanks.

Answer 1

If you want to map consequent characters (say, 'A'..'Z' ) to integer values, I suggest using array :

  using System.Linq;

  ...

  int[] map = new int[] {
    //TODO: put corresponding integer values starting from 'A'
    4, 2, 3
  };  

  ...

  s = "ABC";

  int sum = s.Sum(c => map[c - 'A']);

In general case, if you want to map arbitrary symbols, you can use dictionary :

  using System.Linq;

  ...

  Dictionary<char, int> map = new Dictionary<char, int>() {
    //TODO: put all required pairs here
    {'A', 4},
    {'B', 2},
    {'C', 1},
    {'#', -123},
  };

  ...

  s = "ABC";

  // if there's no map (e.g. for '*'), we assume the value being 0
  int sum = s.Sum(c => map.TryGetValue(c, out int v) ? v : 0);   

Answer 2

http://www.asciitable.com/

you will see that capitol A is 65

string str = "Hi there";
foreach(char c in str.ToUpper())
{
    value += ((int)c) - 64;
}