C++ Variables

Variables are used to store some values (also known as data values). Each variable has a specific type in C++, and it determines the size and layout of the variable's memory. The variable are called 'symbolic' variable because they are named.

There are two values associated with a symbolic variable.

rvalue :- Its data value that is stored in a location in memory. It is also known as rvalue.

lvalue :- Its location value is the address in the memory on which the data is stored. It is also known as lvalue.

There are different types of variable in C++.

1. int :- It stands for the word named "integer" which stores whole number without decimals.

For Example :- 5, -5

2. char :- It stands for the word named "Character" which stores single characters.

For Example :- 'L' or 'f'

3. bool :- It stands for the word named "Boolean" which stores values either true or false.

4. double :- It is used to stores double-precision floating point value.

For Example :- 5.0, -5.5

5. string :- It stores text that is written under double quotation marks.

For example :- "Letsfindcourse30"

5. void :- The void type specifies an empty set of values. An object of type void cannot be declared.

Declaring Variables

To declare a variable, you must specify the variable type and you can specify the value to that variable at that time or later on.

Syntax :

type variable = value;

Where the type can be (int, double, char, bool) and the name of the variable can be (eg var_1, lfc) and the equal sign assign the value to the variable.

Now lets see some examples - we are creating a variable named "number" and its type is "int" and the value is "25".

Example :

int number = 25;
cout << number;

We can also first declare a variable and then we can specify its value later on.

Example :

int number;
number = 25;
cout << number;


We use the keyword constant if we do not want to change the value of the variable or if we do not want to override our existing values. Constant is a keyword that is presented as const.

Example :

const int number = 25;  // number will always be 25
number = 5; // error: assignment of read-only variable 'number'


1. Variable1= expression; which one is evaluated first?

A. variable1
B. expression
C. Both are evaluated equally
D. None of them

View Answer

2. Values stored in a computer system's memory as a sequence of

A. Characters
B. Strings
C. Bits (0 and 1)
D. Float numbers

View Answer

Program :-

C++ Program to Check Whether a character is Vowel or Consonant.

using namespace std;
int main()
char c;
int isLowercaseVowel, isUppercaseVowel;
cout << "Enter an alphabet: ";
cin >> c;
// evaluates to 1 (true) if c is a lowercase vowel
isLowercaseVowel = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');
// evaluates to 1 (true) if c is an uppercase vowel
isUppercaseVowel = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');
// evaluates to 1 (true) if either isLowercaseVowel or isUppercaseVowel is true
if (isLowercaseVowel || isUppercaseVowel)
cout << c << " is a vowel.";
cout << c << " is a consonant.";
return 0;

Output :

Enter an alphabet: u
u is a vowel.

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