C语言见不怪,变量定义放在外
#include <stdio.h> void fun1(); void fun2(); int x=1; int main () { x++; printf("%d\n", x); fun1(); printf("%d\n", x); fun2(); printf("%d\n", x); return 0; } void fun1() { x+=3; } void fun2() { x+=7; }
类比:函数声明的位置
(1)
#include <stdio.h> int gcd(int n1, int n2); int lcm(int n1, int n2); int main() { int num1 = 56 ,num2 =80; int iGcd, iLcm; iGcd=gcd(num1, num2); iLcm=lcm(num1,num2); printf("%d %d\n",iGcd, iLcm); return 0; } int lcm(int n1, int n2) { return n1*n2/gcd(n1, n2); }; int gcd(int n1, int n2) { int r; while(n2!=0) {... } return n1; }
(2)
#include <stdio.h> int main() { int num1 = 56 ,num2 =80; int iGcd, iLcm; iGcd=gcd(num1, num2); iLcm=lcm(num1,num2); printf("%d %d\n",iGcd, iLcm); return 0; } int gcd(int n1, int n2); int lcm(int n1, int n2); int lcm(int n1, int n2) { return n1*n2/gcd(n1, n2); }; int gcd(int n1, int n2) { int r; while(n2!=0) {... } return n1; }
(3)
#include <stdio.h> int main() { int gcd(int n1, int n2); int lcm(int n1, int n2); int num1 = 56 ,num2 =80; int iGcd, iLcm; iGcd=gcd(num1, num2); iLcm=lcm(num1,num2); printf("%d %d\n",iGcd, iLcm); return 0; } int lcm(int n1, int n2) { return n1*n2/gcd(n1, n2); }; int gcd(int n1, int n2) { int r; while(n2!=0) {... } return n1; }