Const Qualifier

Abstract

To make the variable a read-only, we apply the const qualifier to its declaration. Once initialized or assigned to, these variables become read-only. Attempting to change their values results in a compile-time error. Let us write an example that defines a few simple constants:

#include <stdio.h> int main(void) {       const char c = 'a';       const int x = 123;       const double d = 456.789;       printf("We have defined three constants.\n");       printf("Their values are: %c, %d, %.3f.\n", c, x, d); }