Basic C Plus Plus Data Types

Data Type specifies what type of data will be stored in a variable and what type of operations can be performed on it. So, the data type of a variable my be defined as the set of values and operations on these values. For example, if we want to use whole numbers data in our C++ program, we will use int data type variables. int stands for integer data type. int data type has

1. a set of values   -32768 to +32767
2. and predefined operations on these values like +(addition), - (subtraction), *(mutplication) and / (division) etc.

Therefore, it is clear from the above, that we can store a whole number from -32768 to 32767 in an integer variable. Moreover, we can use addition, subtraction, multiplication and division operations on integer variables.
Basic data Types in C++
There are the following data types in C++.

1. integer data types ( int, short int, long int, unsigned int, unsigned long int)
2. real data types (float, double, long double)
3. char

1. Integer Data Types

Integer data types deal with whole numbers. We will define integer variables to store and operate whole numbers. Integer data type is used to define integer variables. integer variables can hold whole numbers that is numbers without fractions or decimal point. For example 100, 8, 991, -2, 786 and 32400 are whole numbers. These whole numbers will range from -32768 to 32767.
Now we can divide integer data types in to some categories according to the memory space they take and the range of whole numbers they can deal with.

•     int data type

int data type deal with whole numbers. in MS-DOS, a variable of int data type takes two bytes in memory. It can store values between the range -32768 to +32767.

•     short int data type

short int data type can store whole numbers from -32768 to +32767. A variable of short int data type will take two bytes in memory.

•     long int data type

long int data type is used to store large whole numbers. It takes four bytes in memory. Its range is from -2,147,483,648 to 2,147,483,647.

•  unsigned int data type  

It is used to store only positive whole numbers from 0 to 65,535. Its variable takes two bytes in memory.

•  unsigned long int data type  

It is used to store only positive whole numbers from 0 to 4,294,967,295. Its variable takes four bytes in memory.

2. Real Data Types

Real data types deal with real numbers, that is, numbers with factional parts or decimal points like 4.50, -90.20, 2.49 and 999.99 etc.

• float data type

float data type deals with real numbers. A variable of float data type will hold four bytes in memory. It can store real values from 3.4x10^-38 to 3.4x10⁺³⁸. A float variable can store real numbers with accuracy of 6 decimal places.

• double data type

double data type deals with large real numbers. A variable of double data type will hold eight bytes in memory. It can store real values from 1.7x10^-308 to 1.7x10⁺³⁰⁸. Moreover, a double variable can store real numbers with accuracy up to 15 decimal places.

• long double data type

double data type deals with very large real numbers. A variable of long double data type will hold ten bytes in memory. It can store real values from 1.7x10^-4932 to 1.7x10⁺⁴⁹³². Moreover, a long double variable can store real numbers with accuracy up to 19 decimal places.

3. Character Data Type

char data type is used to store a single character value. It can store a letter A-Z or a-z, a number 0-9 and some special characters or symbols. A character variable (variable of char data type) takes one byte in memory. It can store a single character. Character value is enclosed in single quotes like 'a' or 't' or '#' etc.