函数的常见样式

#include<iostream>
using namespace std;
 void test1(){
  cout<<"this is test01"<<endl;
 }
 int main(){
  test1();
 }

#include<iostream>
using namespace std;
 void test2(int a){
  cout<<"this is test02="<<a<<endl;
 }
 int main(){
  test2(100);
 }

#include<iostream>
using namespace std;
int test3(){
  //cout<<"this is test03"<<endl;
 return 1;
 }
 int main(){
  int num1=test3();
  cout<<"num1= "<<num1<<endl;
  system("pause");
 }

#include<iostream>
using namespace std;
int test4(int a){
  //cout<<"this is test03"<<endl;
 return a+1;
 }
 int main(){
  int num1=test4(5);
  cout<<"num1= "<<num1<<endl;
  system("pause");
 }