Discussion in 'C#' started by pradeep, May 21, 2007.
C# allows you to define two types of variables: value types and reference types. The value types hold actual values, while reference types hold references to values stored somewhere in memory.
Also value types are allocated on the stack and are available in most programming languages. Reference types are allocated on the heap and typically represent class instances.
sbyte: Holds 8-bit signed integers. The s in sbyte stands for signed, meaning that the variable's value can be either positive or negative. The smallest possible value for ansbyte variable is -128; the largest possible value is 127.
byte: Holds 8-bit unsigned integers. Unlike sbyte variables, byte variables are not signed and can only hold positive numbers. The smallest possible value for a byte variable is 0; the largest possible value is 255.
short: Holds 16-bit signed integers. The smallest possible value for a short variable is -32,768; the largest possible value is 32,767.
ushort: Holds 16-bit unsigned integers. The u in ushort stands for unsigned. The smallest possible value of an ushort variable is 0; the largest possible value is 65,535.
int: Holds 32-bit signed integers. The smallest possible value of an int variable is -2,147,483,648; the largest possible value is 2,147,483,647.
uint: Holds 32-bit unsigned integers. The u in uint stands for unsigned. The smallest possible value of a uint variable is 0; the largest possible value is 4,294,967,295.
long: Holds 64-bit signed integers. The smallest possible value of a long variable is 9,223,372,036,854,775,808; the largest possible value is 9,223,372,036,854,775,807.
ulong: Holds 64-bit unsigned integers. The u in ulong stands for unsigned. The smallest possible value of a ulong variable is 0; the largest possible value is 18,446,744,073,709,551,615.
char: Holds 16-bit Unicode characters. The smallest possible value of a char variable is the Unicode character whose value is 0; the largest possible value is the Unicode character whose value is 65,535.
float: Holds a 32-bit signed floating-point value. The smallest possible value of a float type is approximately 1.5 times 10 to the 45th power; the largest possible value is approximately 3.4 times 10 to the 38th power.
double: Holds a 64-bit signed floating-point value. The smallest possible value of a double is approximately 5 times 10 to the 324th; the largest possible value is approximately 1.7 times 10 to the 308th.
decimal: Holds a 128-bit signed floating-point value. Variables of type decimal are good for financial calculations. The smallest possible value of a decimal type is approximately 1 times 10 to the 28th power; the largest possible value is approximately 7.9 times 10 to the 28th power.
bool: Holds one of two possible values, true or false. The use of the bool type is one of the areas in which C# breaks from its C and C++ heritage. In C and C++, the integer value 0 was synonymous with false, and any nonzero value was synonymous with true. In C#, however, the types are not synonymous. You cannot convert an integer variable into an equivalent bool value. If you want to work with a variable that needs to represent a true or false condition, use a bool variable and not an int variable.
string: Represents a string of Unicode characters. It allows easy manipulation and assignment of strings. Strings are immutable, meaning that once it is created it can't be modified. So when you try to modify a string, such as concatenating it with another string, a new string object is actually created to hold the new resulting string.
object: Represents a general purpose type. In C#, all predefined and user-defined types inherit from the object type or System.Object class.
Proper utilization of correct data types allows developers to make the most of the language, but may take some time for those who have used different programming languages prior to switching to C#. For more information about each type, visit the Microsoft Web site.
Can you tell me why string is reference type and not as value type. I never understood this.
I am not sure and would like to know if this can be done.
for int as well as for string.
string is an Object, that's why we instantiate it! int is not any class/object so, we can't do "new int();"
is for consistency but the allocation is not in heap and its not used as reference and the simple reason I can think of is the compiler never knows what is the type (reference / value) and so for basic types its always the value type.
A user-defined data type such as a class or interface.
I raise this issue long back. Currently imrantechi raise this issue..
Please consider it else you or me or anyone may suffer with a serious problem.
as told by debleena is correct only.. but anyone cant put their name as author. Just put the from MSDN or give the link of msdn.
What I meant is the data/code is not that of author.
By any way it should come into that categories. means article should be deleted.
One thing our aim is to increase the quality of this forum. So Imrantechi told me to do this.
what is meant by this??
If we are going to coping some article from other author then we should responsible to ask him for permission. Then he should tell that i have taken this artiicle from other source(like in u'r case MSDN) then i have to go MSDN' responsible person to ask for permission.
suppose the article(suppose A) which is copied from MSDN that person is responsible i.e. means he may be wrong or have taken permission from msdn.
But this article(by pradeep suppose B) copied from article A or may be from msdn. In both cases it's duplicate of msdn or that article. In both case it's illegal.
First thing shabbir, you are saying duplicate. But do you know the meaning of duplicate???
This is not at all duplicate ... This is illegal Copied from some author article.
there is very big difference b/w duplicate and Illegal copied.
Duplicate: Author gives his same article to different different sites or magazine. Then those article are called duplicate.
Illegal(Unauthorized) Copied: Without taking any permission from aouthor, copied that article .
If he gave the permission then author name should be same author. Only you can advertize in your site with name of that author.