Type conversion and parsing

Conversion is the process of going from one data type to another. This can be done in a couple of different ways: - Casting: convert compatible types (e.g., int → double). - as conversion: safe type conversion between compatible reference types or nullable value types. It attempts to cast an object to a specified type and returns null if the conversion fails, instead of throwing an exception like a direct cast ((Type)obj) would. - Conversion methods: hanging between more diverse types, including incompatible types (e.g., string → int). - Parsing: exclusively for converting strings into numeric types (string → int, double, etc.).

Casting compatible types

• Implicitly casting (safe or automatic) by the programming language:

  int num = 2147483647;
  long bigNum = num;
  

• Explicit (manual) casting by us:

  double x = 1234.7;
  a = (int)x;
  
  //Derivative
  Giraffe g = new Giraffe();
  Animal a = g; // class Giragge : Animal <- base
  

As conversion

object obj = someValue;
SomeType variable = obj as SomeType;


object obj = 123;  // Integer
string str = obj as string;

if (str == null)
{
    Console.WriteLine("Casting failed!"); // Output: Casting failed!
}

Conversion methods

• Handles null values gracefully (returns 0 instead of an exception).
• Works for different types, including bool, DateTime, etc.
• Use when converting between different types (e.g., string to int, double to bool).

string strNum = "42";
int num = Convert.ToInt32(strNum); // Converts string to int

Type conversion methods
ToBoolean
ToByte
ToChar
ToDateTime
ToDecimal
ToDouble
ToInt16
ToInt32
ToInt64
ToSbyte
ToSingle
ToString
ToType
ToUInt16
ToUInt32
ToUInt64

Parsing strings

Using Parse():

string strNum = "42";
int num = int.Parse(strNum); // Returns an exception if the parse fails.

Using TryParse() is safer because it returns true if parsing succeeds, false otherwise.

string strNum = "42";
bool success = int.TryParse(strNum, out int num);