The data type is a very important concept in C/C++. Every data (constant or variable) is of a certain type. The data type specifies what values that data can have and what operations can be performed on it.
In C/C++, the data types are:
Simple Types
The int Type
The float and double Types
The char Type
The pointer Type
The bool Type
The void Type
Derived Types
The Array Type
The Structure/Class Type
The Enumeration Type
The int Type
allows storing integer values - positive or negative;
an int occupies (usually) 4 bytes; thus, it can store integer values from [-2,147,483,648, 2,147,483,647]
The float and double Types
store real numbers;
the decimal separator is the dot ".";
they are also called floating-point types;
real data can be given in fixed or scientific (exponential) form;
float type is represented on 4 bytes;
double type is represented on 8 bytes.
The char Type
is used for ASCII characters;
stores a single character;
it is represented on 1 byte;
characters are delimited by apostrophes " ' ".
The void Type
the word void means "nothing" or "without value";
void data have no values and no operations can be performed with them;