Data Types

Question

This book didn't tell about how many bytes are string  char and bool . I wish to know why. I attach the book page.

Vulpes · Answer

I don't know why the size of those types wasn't included in the list though they are as follows: bool 1 byte char 2 bytes string 16 bytes plus 2 bytes per character plus 2 bytes for the final null character. In the rare cases of 'surrogate pairs' (characters which can't be represented within the normal unicode range) the char type requires 4 bytes rather than 2 bytes. 64-bit versions of Windows require 8 bytes more storage for strings than the above formula gives. The null character at the end of strings isn't actually part of the string but is needed for interop with unmanaged code.

Vulpes · Answer

Incidentally Maha you can find out the size in bytes of any value type using the sizeof keyword: using System; class Test { static void Main() { Console.WriteLine(sizeof(bool)); // 1 Console.WriteLine(sizeof(char)); // 2 Console.ReadKey(); } } Unfortunately sizeof doesn't work with reference types such as string.

Maha · Answer

Thank you for your explanation.

Vulpes · Answer

An instance of System.Object (or 'object' to use its C# alias) requires 12 bytes of storage on a 32 bit system or 24 bytes on a 64 bit system. 8 bytes of this (16 bytes on a 64 bit system) is overhead which all objects need for various purposes. The remaining 4 bytes (8 bytes on a 64 bit system) is the minimum amount of memory which must be allocated to contain an object's fields. As System.Object has no fields the minimum figure is used.

Maha · Answer

How many byte object data type is?

Maha · Answer

Thank you for your explanation.

Vulpes · Answer

The chart is in fact wrong. The size of a decimal is 16 bytes.

Maha · Answer

In the above Data Types chart decimal size is 8 but according to following program decimal size is 16. Please explain the reason for variation. using System; class Test { static void Main() { Console.WriteLine(sizeof(decimal)); //16 Console.ReadKey(); } }

Maha · Answer

Thank you for addition.

Maha · Answer

Thank you for your help.