Float numbers and others

Question

I am very confused regarding Float, Long and double long,I want to know all the basic differences about them.Is there anyone who can clear my confusions

Satyapriya Nayak · Answer

Hi Emmy, Predefined C# value types 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. Refer http://www.go4expert.com/forums/showthread.php?t=4382 Thanks

Maha · Answer

C# Data Types given in the book

Vulpes · Answer

C# doesn't have a 'long double' type but C++ does so I presume you must be talking about C++ here. Although it's implementation defined, long double often represents a 10 byte floating point number which is accurate to 19 or 20 digits. This contrasts with the double type (always 8 bytes) which is accurate to 15 or 16 digits. However, in Win32 programming using Microsoft's Visual C++ compiler, long double is exactly the same as double. The long type is also implementation defined in C++ but in Win32 programing is the same as int (4 bytes). The float type is always a 4 byte floating point number, accurate to 7 digits, AFAIK. Notice that even if you're only using the float or double types, floating point arithmetic is normally carried out internally to a greater precision (10 bytes or more) and the result is then rounded off to 4 or 8 byte accuracy.