C Variables

A variable is a data name that may be used to store a value. Unlike constant variables are also remain unchanged during the execution of a program. A variable name should be chosen in a meaningful way so that it relects its function or nature in the program. There are some rules for choosing a variable name. They are following:

• Must begin with a letter or underscore.
• First 31 characters are significant.
• Variables name are case sensitive.
• consist of Capital letters(A-Z), lowercase letters(a-z), digits(0-9), and the underscore character.
• Should not be a keyword.
• White space is not allowed.
• Special characters are not allowed.

There are the following variable types in C language:

Example of a c program using variable is given below:

#include <stdio.h>
int main()
{
    int first_number, second_number, sum;
    
    printf("Enter two integers: ");
    scanf("%d %d", &first_number, &second_number);
    sum = first_number + second_number;
    printf("%d + %d = %d", first_number, second_number, sum);
    return 0;
}

Enter two integers: 7
            17
            7 + 17 = 24