DATA TYPES IN C++

DATA TYPES IN C++ 

Whenever you create a variable to store a value, you also define the data type of that variable as well. From data type, the compiler knows which type of data will be stored in this variable.

Also, from compiler data type, it also decides how much space is to be assigned in memory to a variable. The data types in C ++ are divided into 3 categories.

     1. BASIC/PRIMARY DATA TYPE :  As I told you earlier basic data types are almost common in all programming languages. Basic/primary data types are in the 6 categories given below.

1.     Integer
2.      Character
3.      Boolean
4.      Void
5.       Floating point
6.       Double floating point

These are being given in detail below.

                                           
Integer : The data types of Integer category are used to store the whole number. Whole numbers are numbers that do not contain decimals and numbers after it. These are whole numbers. Keyword used for integer data types is int. Integers typically requires 4 bytes of memory space and ranges from -2147483648 to 2147483647.

           Character : If you want to store a character instead of a number, for this you can use the data types of this category. Keyword used for character data type is char. Characters typically requires 1 byte of memory space and ranges from -128 to 127 or 0 to 255.

           Boolean : Boolean data type is used for storing boolean or logical values.A boolean variable can store either true or false. Keyword used for boolean data type is bool.

            Void : Void means without any value. void datatype represents a valueless entity. Void data type is used for those function which does not returns a value.

             Floating point : Floating Point data type is used for storing single precision floating point values or decimal values. Keyword used for floating point data type is float. Float variables typically requires 4 byte of memory space.

           Double floating point : Double Floating Point data type is used for storing double precision floating point values or decimal values. Keyword used for double floating point data type is double. Double variables typically requires 8 byte of memory space.

            

            2. DERIVED DATA TYPE : Derived data types are those derived from basic data types. Derived data types do not create any new data types, instead add some functionality to the basic data types itself. There are 4 types of derived data types found in C ++.

1.             FUNCTION
2.             ARRAY
3.             POINTER
4.             REFERENCE

You will read all these in detail in further tutorials.

     3. USER DEFINE DATA TYPE : User defined data types are the data types that you define as programmer. You have already read about user defined data types in C Language. In C Language you were told about Struct and Union which are data types of the same category.

     These data types are also fully allowed in C ++. Also C ++ provides you the capabilities to create some new user define data types that are suitable for object oriented programming. They are being told below.

         CLASS  : Class is also like struct. But of struct you cannot create object and classes is the base of object oriented programming. Like struct you can also create variables in classes and at the same time you can also create functions in classes. You will be told about the class in detail in classes and objects tutorial.
   STRUCTURE : Structure This is a collection of different data types. If the structure is to be used, then use the keyword 'struct'. Structure is similar to array. Array is a collection of similar data types and Structure is a collection of different data types. Structure allocates different memory for each member.
   UNION : Union is a collection of different data types. If you want to use union, then use the keyword 'union'. Union is similar to this structure. Union does not allocate different memory for each member. Union members share the same memory location. If a member in a union is larger in size, then it is the size of the entire union.
   ENUM : An enum data type is a user define data type that attaches numbers with names. This makes it easier to use code. To create an enum data type, you use the enum keyword. After the enum keyword, you give the name of the variable. All values are written inside curly braces separated by (,). These names are automatically assigned values ranging from 0 to values using the enum keyword.