Char to Int explicit Conversion in C#

Question

I was trying to learn explicit conversion in c#.

First I explicitly converted string to int

namespace MyfirstCSharpCode
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = "1234";
            int i = Convert.ToInt16(str);
            Console.WriteLine(i);

        }
    }
}

it worked and the result is : 1234

Now I tried to convert char to int

namespace MyfirstCSharpCode
{
    class Program
    {
        static void Main(string[] args)
        {
            char str = '1';
            int i = Convert.ToInt16(str);
            Console.WriteLine(i);

        }
    }
}

And now the result is 49, the ASCII value of 1. How to get the char 1 instead of ASCII value. Please don't be too harsh its my first day in c# ;)..

@AlexK. - Thanks bro..Yes it worked. It is like trying to convert the ASCII value back to Character. Why it is converted to `ASCII` value instead of `Int`. — Pரதீப், May 27 '17 at 14:45
you hit the overload methods of `Convert.toInt16` , use `Int.tryParse` for int assignment before using `Convert.ToInt16` — Turbot, May 27 '17 at 14:45
"Why it is converted to ASCII value instead of Int." It's not clear what you mean. A `char` is a UTF-16 code unit. The integer value of the UTF-16 code unit representing '1' is 49. That's how it's defined. It sounds like you want to look at `char.GetNumericValue`. — Jon Skeet, May 27 '17 at 14:45
@JonSkeet - When I use `int i = Convert.ToInt16(str);` why it is converted to `ASCII` value `49` instead of `int` value `1` — Pரதீப், May 27 '17 at 14:47
@Prdp: And I've explained that to you. It's giving you the UTF-16 code unit value. It's not trying to parse it as if it were a digit - that's what `char.GetNumericValue` is for. — Jon Skeet, May 27 '17 at 14:48
Someone care to write answer though it might not be a new or useful question :/ so that we can close the question — Pரதீப், May 27 '17 at 14:50
@Turbot - when I did this `int i = int.tryParse(str);` I got a error saying *int does contain a definition for tryparse*. May be am missing something — Pரதீப், May 27 '17 at 14:55
C# is case sensitive. It is `int.TryParse` (it returns a bool and has an out parameter that contains the parsed value). You can also use `int.Parse` if you want the int value immediately, though it would throw an exception if it is an invalid int value. — Styxxy, May 27 '17 at 15:13

Turbot · Accepted Answer · 2017-05-27T15:31:29.670

You hit the overload methods of Conver.ToInt16(char) , and char is a UTF-16 code unit and representing 1 is 49. You can use Int16.TryParse to safe parse the number (need in 16 bit sign number) in order to get the valid integer.

               string str = "1";  //  use string if your number e.g 122
               short number;  // convert to 16 bit signed integer equivalent.
               if (Int16.TryParse(str, out number))
               {  
                   Console.WriteLine(number);

               }

Char to Int explicit Conversion in C#

1 Answers1