C/Data Type/Constant

Calculate a discounted price

<source lang="cpp">

1. include <stdio.h>

int main() {

 const int level1 = 30;
 const int level2 = 50;
 const double discount1 = 0.10;
 const double discount2 = 0.15;
 const double unit_price = 3.50;
 int q1 = 0;
 int q2 = 0;
 int qty_over_level1 = 0;
 int qty_over_level2 = 0;
 printf("Quantity?: ");
 scanf("%d", &q1);
 q2 = q1;
 qty_over_level2 = q1%level2;
 q1 -= qty_over_level2;
 qty_over_level1 = q1%level1;
 q1 -= qty_over_level1;
 printf("\nThe total price for %d is $%.2lf\n", q2,
   unit_price*(q1+(1.0-discount1)*qty_over_level1+(1.0-discount2)*qty_over_level2));

}

      </source>

Cannot assign value to a constant variable

<source lang="cpp">

1. include <stdio.h>

int main(void) {

 const int i = 10;
 i = 20; /* this is wrong */
 printf("%d", i);
 return 0;

}

      </source>

Convert inches to yards, feet, and inches

<source lang="cpp">

1. include <stdio.h>

void main() {

 int inches = 0;
 int yards = 0;
 int feet = 0;
 const int inches_per_foot = 12;
 const int feet_per_yard = 3;
 printf("Enter a distance in inches: ");
 scanf("%d", &inches);
 feet = inches/inches_per_foot;
 yards = feet/feet_per_yard;
 feet %= feet_per_yard;
 inches %= inches_per_foot;
 printf("That is equivalent to %d yards %d feet and %d inches.\n",
                                                   yards, feet, inches);

}

      </source>

Define a constant value

<source lang="cpp">

1. include <stdio.h>

int main(void) {

 const int i = 10;
 printf("%d", i); 
 return 0;

}

      </source>