如何让c语言使用结构体近似模拟c++中的类

如今统治市场的主流编程语言，如c++，java，大都是面向对象类型的编程语言。

而众所周知，c语言是面向过程的编程语言，但是它拥有一个类似于类的结构，叫做结构体，主要的区别在于结构体无法定义函数。

因此，为了c语言的结构体近似模拟类，我们可以在结构体中定义函数指针。

下面这个例子，是最常用的计算学生分数平均数的c++类模版：

#include <cstdio>

#include <iostream>

#include <cstdlib>

#define LINE for (i = 0 ; i < 60 ; i++) {printf("-");}printf("\n");

#define SPACE for (i = 0 ; i < 20 ; i++) printf(" ");

using namespace std;

class Student

{

public:

	double stuAvg(double score[]);

	int num;

	char name[10];

	double score[3];

	double average;

};

double Student::stuAvg(double score[]){

	double sum = 0.0;

	double average = 0.0;

	for (int i=0 ; i < 3 ; i++)

	{

		sum += score[i];

	}

	return average = sum/3;

}

int main(void){

	Student stu1;

	for (int i = 0 ; i < 3 ; i++)

	{

		scanf("%lf",&stu1.score[i]);

	}

	stu1.num = 1001;

	memset(stu1.name,0,sizeof(stu1.name));

	strcat(stu1.name,"Peter");

	stu1.average = stu1.stuAvg(stu1.score);

	//Output Part

	printf("NUM");

	SPACE;

	printf("NAME");

	SPACE;

	printf("AVERAGE");

	printf("\n");

	LINE;

	printf("%d",stu1.num);

	SPACE;

	printf("%s",stu1.name);

	SPACE;

	printf("%.2lf",stu1.average);

	printf("\n");

	LINE;

	return 0;

}

接下来我们使用结构体模拟上例中类的作用：

#include <stdio.h>

#include <stdlib.h>  

#define LINE for (i = 0 ; i < 60 ; i++) {printf("-");}printf("\n");

#define SPACE for (i = 0 ; i < 20 ; i++) printf(" ");    

struct Student{

    double (*stuAvg)(double score[]);

    int num;

    char name[10];

    double score[3];

    double average;

};  

double Calc_Avg(double score[]){

    int i = 0;

    double sum = 0.0;

    double average = 0.0;

    for (i=0 ; i < 3 ; i++)

    {

        sum += score[i];

    }

    return average = sum/3;

}  

void main(void){

	int i = 0;

    struct Student stu1;

    for (i = 0 ; i < 3 ; i++)

    {

        scanf("%lf",&stu1.score[i]);

    }

    stu1.num = 1001;

    memset(stu1.name,0,sizeof(stu1.name));

    strcat(stu1.name,"Peter");

    stu1.stuAvg = Calc_Avg;

    stu1.average = stu1.stuAvg(stu1.score);  

    //Ouuput Part  

    printf("NUM");

    SPACE;

    printf("NAME");

    SPACE;

    printf("AVERAGE");

    printf("\n");

    LINE;

    printf("%d",stu1.num);

    SPACE;

    printf("%s",stu1.name);

    SPACE;

    printf("%.2lf",stu1.average);

    printf("\n");

    LINE;

    return;

}

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如何让c语言使用结构体近似模拟c++中的类

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