Question

我正在探索C ++中结构的所有可能性，当我谈到结构指针时，我遇到了一些运行时错误。

这是我的代码：

    #include<iostream>
#include<string>
using namespace std;

// globally defined structure can be used in any method
struct stud
{
    int roll;
    string sname;
    // nested structure for date of birth
    struct dob
    {
        int date;
        int month;
        int year;
    } dob1;
    int marks1;
    int marks2;
    int marks3;
} stud1 = {1,"pranshu1",{11,4,1993},65,87,80};

// function to calculate average of a student
float calaverage(stud s1)
{
    float savg=s1.marks1+s1.marks2+s1.marks3;
    savg=savg/3;
    return savg;
}

// function to calculate the average of whole class
// function parameter are the starting address of the array of the structure stud 
// and the total no of elements in the array
float avgclass(stud *ptr, int no_of_stud)
{
    float classtotal=0;
    for(int i=0;i<no_of_stud; i++)
    {
        classtotal=classtotal+calaverage(*(ptr+i));     
    }
    return classtotal;
}

int main()
{
    // array of structure
    struct stud class1[3]=
    {
    stud1,
    {2,"pranshu2",{11,4,1993},80,95},   
    {3,"pranshu3",{11,4,1993},64,84,93}
    };
    // initializing the value by accessing the member
    class1[0].marks3=93;
    struct stud* stud5;
    stud5->roll=10;
    stud5->sname="pranshu";
    stud5->dob1.date=11;
    stud5->dob1.month=4;
    stud5->dob1.year=93;
    stud5->marks1=97;
    stud5->marks2=45;
    stud5->marks3=98;


    cout<<stud5->roll<<endl;
    // average marks of student 1
    cout<<"Average marks of "<<stud1.sname<<" with roll no "<<stud1.roll<<" is "<<calaverage(stud1)<<endl;

    // class average
    cout<<"Class average is "<<avgclass(class1,3)<<endl;
}

错误与stud5有关，但我没有得到任何关于它的线索..

Answer 1

struct stud* stud5;只是一个指针......你还应该分配内存：

stud5 = new stud;

拥有一个物体。

指向结构的指针中的运行时错误

1 个答案: