C++引用数组，函数指针，函数指针数组，结构体数组等学习

这篇博文主要介绍了如何在C++11  VS2013编译器上去实现各种引用，避免因为编译器不同造成的语法困难

1：引用数组，二维数组 ，数组指针

#include <iostream>
using namespace std;

void main1(){
    
	/*int a[3]{1,2,3};
	int aa[2][3]{1,2,3,4,5,6};
	int*pa(new int[3]{1,2,3});
	int(*paa)[3](new int[2][3]{1,2,3,4,5,6});*/
	//int(*paa)[3] = new int[2][3]{{ 1, 2, 3 }, { 4, 5, 6 }};

	int a[3]{1,2,3};
	int* pa[3] = { a, a + 1, a + 2 };

	int(&ra)[3](a);         //引用一个数组
	int*(&raa)[3](pa);      //引用一个指针数组
	for (auto i : ra){
		cout << i << endl;
	}

	for (auto i : raa){
		cout <<*i<< endl;
	}


	cin.get();
}

void main2(){

	//堆上的一维数组
	int*p1(new int[3]{22, 33, 44});
	    
	int*(*p2)(new int*[3]{p1,p1+1,p1+2});

    //引用指针
	int(*(&fp))(p1);

	int(**(&fpp))(p2);

	for (int i = 0; i < 3;i++){
		cout <<fp[i] <<endl;
	}

	for (int i = 0; i < 3; i++){
		cout << *fpp[i] << endl;
	}


	cin.get();
}

void main3(){

	int pp[2][3]{33,44,55,11,22,99};
	int* ppp[2][3]{&pp[0][0],&pp[0][1],&pp[0][2],&pp[1][0],&pp[1][1],&pp[1][2]};

	//引用二位数组
	int(&fp)[2][3](pp);

	//引用指针二位数组
	int*(&fpp)[2][3](ppp);

	for (int i = 0; i < 2; i++){
		for (int j = 0; j < 3; j++){
			cout << fp[i][j] << endl;
		}
	}

	for (int i = 0; i < 2; i++){
		for (int j = 0; j < 3; j++){
			cout << *fpp[i][j] << endl;
		}
	}

	cin.get();
}

void main5(){

	//堆上二维数组
	int(*p)[3] = new int[2][3]{{22,33,44},{55,66,77}};
	//int*(*p)[3] = new int*[2][3]{{&p[0][0],&p[0][1],&p[0][2]}, {&p[1][0],&p[1][1],&p[1][2]}};

	//引用二维数组指针
	int(* &fp)[3](p);    //引用一个行指针

	for (int i = 0; i < 2; i++){
		for (int j = 0; j < 3; j++){
			cout << fp[i][j] << endl;
		}
	}

	cin.get();
}
二：函数指针的引用，包括返回值是函数指针

#include <iostream>

using namespace std;


int showcmd(char* cmd){

	cout << cmd << endl;
	return 0;
}

int changeCmd(char* cmd){
	cout <<"ShaoZHongqi"<< endl;
	return 0;
}


//引用函数指针进行切换
void changeFunc(int(* &myfun)(char* cmd)){
	myfun = changeCmd;
}

//返回值是函数指针的引用
int(*& getMyFun())(char* cmd){
	
	//返回一个函数指针
	int(*p)(char* cmd) = showcmd;

	return p;
}

//返回函数指针
int(* getRFun( int(*& myfun )(char* cmd) ))(char* cmd){
	myfun = changeCmd;
	return myfun;
}

//返回函数指针的引用
int(*& getRFun2(int(*& myfun)(char* cmd)))(char* cmd){
	myfun = showcmd;
	return myfun;
}

int(*& getMyRFun())(char* cmd){
	int(*& pp)(char*  cmd)((int(*&)(char*  cmd))(showcmd));
	return pp;
}




void maintest2(){
	
	int(*fun)(char* cmd)(showcmd);

	changeFunc(fun);

	fun = getMyFun();

	//fun("Beijing22");

	getRFun2(fun)("Nanjing2222");

	getMyRFun()("123");

	cin.get();
}

三:函数指针数组的引用

#include <iostream>
using namespace std;

int add(int a, int b){
	return a + b;
}

int plusp(int a,int b){
	return a - b;
}

int dubplite(int a, int b){
	return a*b;
}


void maintest(){

	int(*fun[3])(int, int){add,plusp,dubplite};

	//二级函数指针数组

	int(**funarray)(int, int){ new (int(*[3])(int, int)){ add, plusp, dubplite} };

	//引用函数指针
	int(* (&pf)[3])(int, int)(fun);

	int(** &pff)(int, int)(funarray);

	for (int i = 0; i < 3; i++){
		cout << pf[i](100, 10) << endl;
	}

	//遍历函数指针数组
	for (int(** px)(int, int) = pff; px < pff + 3;px++){
		cout << (*px)(100, 10) << endl;
	}

	cout << "Nanjing" << endl;
	cin.get();
}

四：引用结构体数组

#include <iostream>
using namespace std;

struct info{

	int id;
	int num;
	info(int nid,int nnum):id(nid),num(nnum){

	}

};


void main(){

	struct info infoarray[3]{{1,11}, {2,22}, {3,33}   };
	for (auto i : infoarray){

		cout << i.id  << "====" << i.num << endl;

	}


	struct info(&finfo)[3](infoarray);
	for (auto i : finfo){

		cout << i.id << "====" << i.num << endl;

	}

	info* pinfoarray{ new info[3]{{ 1, 11 }, { 2, 22 }, {3,33} } };
	for (info*p = pinfoarray; p < pinfoarray + 3;p++){
		cout <<  p->id << "====" << p->num << endl;
	}

	cout << "Nanjing" << endl;
	cin.get();
}