Variables

Variables are like containers which holds the data values. A variable specifies the name of the memory location.

How to declare variables

data-type variable-name = value;

In the above syntax, assigning value is optional as you can just declare the variable and then assign value at later point in the program. Also, the value of a variable can be changed at any time.

Naming convention of variables

• Variable names can have only letters (both uppercase and lowercase letters), digits and underscore(_).
• Variables naming cannot contain white spaces like first name which is a invalid variable name.
• First letter of a variable should be either a letter or an underscore(_).
• Variable type can't be changed once declared as C++ is a strongly typed language.
• In C++, Variable names are case sensitive and hence Name and name both are different.
• It is always advisable to give some meaningful names to variables.

Example

int x = 10; // declaring int variable and assigning value 10 to it
char grade = 'A'; // declaring char variable and assigning value A to it

The above can also be written like below

int x; // declaring int variable 
char grade; // declaring char variable 

x = 10; // assigning value 10 to x variable
grade = 'A'; //and assigning value A to grade variable