What are C++ Variables?

C++ variables are named containers that stores values. In C++ there are different types of variables, which specifies the size and range of the variable’s memory and set of operations that can be performed with the variable.

Naming C++ Variable:

C++ variable can be created with letters, digits and a underscore.
The name can start with either a letter or an underscore. C++ is case-sensitive, hence upper and lowercase letters are different.

Other rules for creating variable names in C++:

– Variable names cannot be a Keyword
– The variable name cannot contain spaces in it
– Special characters like, Hyphen(-), etc.. cannot be used in the variable names
– Variable names cannot start with special characters or numbers. It should start    with either an uppercase or lowercase character or an underscore.

Syntax:

type variable_Name = val

Examples
Valid variable names:
int number;
int _number;
int student_roll;
int studentRoll;

Invalid variable names:
int #roll;
int 2ndstudent;
int student-roll;
int float;
int student roll;

Types of Variables:

int – Stores integer values, like 55 or -1
bool – stores either true or false
double – stores floating point value, like 1.3 or -1.3
char – stores single character like ‘a’ or ‘A’. A single octet value. Char values are quoted in single quotes
string – stores text, like “Welcome to C++”. String values are quoted in double quotes

Declaring variable in C++:

C++ Compiler checks for the variable declaration with the given type and name, to proceed the compilation
int a, b;

Initializing variable in C++:

Assigning values to the variables.
a=1;
b=2;

Example:

int a = 1;
int b = 2;
int add = a + b;
cout << add;