Can and Cannot of Converting Types in ASP.NET 2.0

Implicit conversion is prohibited in C# so that you don’t loose precision of a number for example. However, implicit conversion is allowed if no such loose can occur for example converting from int to double will not be a problem. Such mechanism is called “widening conversion” opposite to it is “narrowing conversion” which requires to perform explicit conversion.

Several methods of conversion are available:

  • System.Conver - used between types those implement System.IConvertible Interface. If conversion is not possible with IConvertable system throws an exception InvalidCastException.
  • (type) – used between types that define conversion operators.
  • type.ToString, type.Parse – used between string and base types. Note ToString also returns be default name of the type.
  • type.TryParse, type.TryParseExact – from string to base type and returns false if not possible.
struct TypeA
    public int Value;

    // Implicit conversion from an integer.
    public static implicit operator TypeA(int arg)
        TypeA res = new TypeA();
        res.Value = arg;
        return res;
    // Explicit conversion to an integer
    public static explicit operator int(TypeA arg)
        return arg.Value;