我从结构开始,但在动态分配结构数组时遇到问题。我正在做我在书中和在互联网上看到的事情,但我做对了。

这都是完整的错误消息:

C2512:“记录”:没有合适的默认构造函数

IntelliSense:类“Record”不存在默认构造函数

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

const int NG = 4; // number of scores

struct Record
{
    string name;  // student name
    int scores[NG];
    double average;

    // Calculate the average
    // when the scores are known
    Record(int s[], double a)
    {
        double sum = 0;

        for(int count = 0; count != NG; count++)
        {
            scores[count] = s[count];
            sum += scores[count];
        }

        average = a;
        average = sum / NG;
    }
};

int main()
{
    // Names of the class
    string names[] = {"Amy Adams", "Bob Barr", "Carla Carr",
                      "Dan Dobbs", "Elena Evans"};

    // exam scores according to each student
    int exams[][NG]= {  {98, 87, 93, 88},
                        {78, 86, 82, 91},
                        {66, 71, 85, 94},
                        {72, 63, 77, 69},
                        {91, 83, 76, 60}};

    Record *room = new Record[5];


    return 0;
}

最佳答案

错误很明显。在您尝试分配数组时:

Record *room = new Record[5];

必须实现默认的构造函数Record::Record(),以便可以创建Record的5个实例:
struct Record
{
    ...
    Record() : average(0.0) { }
    Record(int s[], double a) { ... }
};

还要注意,在C++中,您要避免动态分配(除非您有充分的理由这么做)。在这种情况下,改为使用std::vector更为合理:
std::vector<Record> records(5);

关于c++ - 错误C2512:没有合适的默认构造函数(不是类),我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/19850765/

10-12 14:58
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