Variable Declaration in C With Example

Variable Declaration in C With Example

In this tutorial, you will learn the variable declaration in C language. A variable is an identifier or a name that is used to refer to a value and this value varies or changes during the program execution. A variable is written with a combination of letters, numbers, and special characters or underscores with the first letter being an alphabet. A maximum of 31 letters can be used to write a variable.


x, fact, c22, total_values etc.

Also read, Constant in C with example

Consider the below points while variable declaration in C language

  • Uppercase and lowercase alphabets are taken differently. For example, the variables ‘SUM’ and ‘sum’ are pointing to different values.
  • No special characters other than underscore(_) are permitted.
  • Some C compilers will not accept more than 8 characters. So it is better to declare a variable with a few letters that make it easy to use.
  • All the variables used in the C program are declared with the appropriate data types before assigning a value to that variable. For eg:- int intNum = 3;
  • reserved words can not be used as variables.

Lets us take an example below

#include <stdio.h>
int main() {
  // Create variables
  int intNum = 3;               // Integer (whole number)
  float floatNum = 3.99;     // Floating point number
  char letter = 'C';         // Character

  // Print variables
  printf("%d\n", intNum);
  printf("%f\n", floatNum);
  printf("%c\n", letter);
  return 0;


Variable Declaration in C With Example

Conclusion:- I hope this tutorial will help you to understand the overview of variable declaration. If there is any doubt then please leave a comment below.

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