const.c

里面包含很多c语言的源码

/* Demonstrates variables and constants */
#include <stdio.h>

/* Define a constant to convert from pounds to grams */
#define GRAMS_PER_POUND 454

/* Define a constant for the start of the next century */
const int TARGET_YEAR = 2010;

/* Declare the needed variables */
long weight_in_grams, weight_in_pounds;
int year_of_birth, age_in_2010;

int main( void )
{
    /* Input data from user */

    printf("Enter your weight in pounds: ");
    scanf("%d", &weight_in_pounds);
    printf("Enter your year of birth: ");
    scanf("%d", &year_of_birth);

    /* Perform conversions */

    weight_in_grams = weight_in_pounds * GRAMS_PER_POUND;
    age_in_2010 = TARGET_YEAR - year_of_birth;

    /* Display results on the screen */

    printf("\nYour weight in grams = %ld", weight_in_grams);
    printf("\nIn 2010 you will be %d years old\n", age_in_2010);

    return 0;
}