请问各位大神这个putchar('0'+r)是什么意思?又是怎样输出的弄了好久好都没懂
/*以二进制形式输出整数*/#include <stdio.h>void to_binarry(unsigned long n);int main (void ){ unsigned long number; printf ("Enter an integer(q to quit):\n"); while (scanf("%ul",&number)==1) { printf("Binarry equivalent:"); to_binarry(number); putchar('\n'); printf("Enter an integer (q to quit):\n"); } printf("Done.\n");}void to_binarry(unsigned long n )//递归函数。{ int r; r = n % 2; if (n>=2) { to_binarry(n/2);
} putchar ('0'+ r ); return;