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Examples of some valid variable names are:
Valid Variable Name Reason
Gaurav123 Starts with a letter
_usha93 Starts with an underscore symbol
Examples of some invalid variables are:
Invalid Variable Name Reason
1_Name Cannot start with a digit
@Address Cannot starts with a special symbol (except _ )
int Keyword cannot be used as variable name
User Name Spaces are not allowed in variable names
Declaring a Variable
C++ is a strongly-typed language, which means you need to declare a variable before using it.
You also need to specify the data type of the variable, so that the compiler understands how the
variable is interpreted. When a variable is declared, the computer reserves memory space for it.
Syntax to declare a variable in C++ is as follows:
data_type variable_name;
Where, data_type specifies the type of value a variable can store (e.g., int, float, char) and
variable_name is the name of the variable which is used to access the variable in the program.
For example:
int age;
char grade;
Where, int and char are the data types, and, age and grade are the variable names. You can also
declare multiple variables of the same type in a single line in the following way:
int emp_code, age, pincode;
Initialising a Variable
Initialising a variable means to assign a value to the variable. You can assign a value to a variable
using the assignment operator (‘=’) in the following way:
age = 21; // initialising an integer variable
grade = 'A'; // Initialising a character variable
In the above example, you can see that the single quotes (' ') are used to initialise a character
variable. A variable can also be initialised during their declaration itself in the following way:
int age = 21;
char grade = 'A';
Let's write a program to show this concept more clearly.
17
Getting Started with C++

