Class memory in C#

Question

Hi friends I have a class which have 2 variable one char and one integer in this case how much memory a class can have.

Vulpes · Answer

Chintan's correct about the memory used by the various fundamental types but he hasn't said anything about the overhead needed when allocating objects on the heap and about the alignment of fields within an object based on something called the 'pack size'. However, his figures for the object and string types do in fact include the overhead when objects of these types are created individually.

Akshay Teotia · Answer

Hi chintan r u sure about ur answer please see the description of Vulpes.

Chintan Rathod · Answer

Type Size in Bytes Description Minimum Maximum bool 1 Named literal false true sbyte 1 Signed byte -128 127 byte 1 Unsigned byte 0 255 short 2 Signed short integer -32768 32767 ushort 2 Unsigned short 0 65535 int 4 Signed integer -2147483648 2147483647 uint 4 Unsigned integer 0 4294967295 long 8 Signed long int -9.2233E+18 9.2233E+18 ulong 8 Unsigned long int 0 18446E+19 char 2 Unicode character, contained within single quotes. 0 128 float 4 floating point -3.402823E+38 3.402823E+38 double 8 Floating point -1.7976931E+308 1.7976931E+308 decimal 16 Floating point, accurate to the 28th decimal place. -7.9228E+24 7.9228E+24 object 8+ Base type for all other types n/a n/a string 20+ Immutable character array n/a n/a DateTime 8 Represents an instant in time, typically expressed as a date and time of day. 00:00:00 01/01/0001 23:59:59 31/12/9999 So as you can see size of int and char is 4 and 2 respectively, size of class is 6 bytes. Thank You.

Vulpes · Answer

Well, a char field requires 2 bytes and an int field requires 4 bytes, making 6 bytes in total. However, on a 32 bit system, each object of a class requires 8 bytes of overhead and on a 64 bit system the overhead is 16 bytes. So, the total heap memory needed will be at least 14 bytes (32 bit system) or 22 bytes (64 bit system). Also, to improve processor efficiency, the fields of an object may not be laid out contiguously. Any 'unused' bytes between fields will therefore further increase the memory needed for the object.

Class memory in C#

Answers (4)