Constants in C language
In this article we will see a small example of using constants in c. constants are declared with a keyword const.
const float PI = 3.14 ; //constant of type float
const char myStr[] = ” *** www.ProgrammingPosts.blogspot.com *** ” ; //constant of char array
const char myStr[] = ” *** www.ProgrammingPosts.blogspot.com *** ” ; //constant of char array
The program below is to find the area and perimeter of circle in which we use const .
In the program below we have declared PI as a constant which value is given as 3.14
It means PI value cannot be changed either at compile time or run-time . if we try to change the value of a constant variable it gives a compile-time error.Any Integral or char/string variables can be declared as constants.
Sample Output :
In the program below we have declared PI as a constant which value is given as 3.14
It means PI value cannot be changed either at compile time or run-time . if we try to change the value of a constant variable it gives a compile-time error.Any Integral or char/string variables can be declared as constants.
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#include<stdio.h> int main() { const float PI = 3.14 ; const char myStr[] = "*** www.ProgrammingPosts.blogspot.com ***" ; int r=0; float area; float perimeter; printf("%s n",myStr); printf(">>> c Program to find Area and Perimeter of Circle <<<"); printf("nEnter radius value: "); scanf("%d",&r); //taking radius as input area = PI * r * r; //getting area of circle printf("nArea of circle is: %f" , area); //if we try to assign a value to PI or myStr , we get compile-time error //PI = 123; perimeter = 2 * PI * r; //getting perimeter of circle printf("nPerimeter of circle: %f" , perimeter); getch(); } |
Sample Output :
