Question

尽可能简单地询问是否可以解释为什么这个代码：

LinkedListByGrade::LinkedListByGrade(vector<Node> myNodes) {
int lowestGradeFound = myNodes[0].getGrade();
Node *pFristNode = new Node();
cout << "New node created" << endl;
for (size_t i = 0; i <= myNodes.size(); i++) {
    if (myNodes[i].getGrade() < lowestGradeFound) {

        cout << "if triggered" << endl;
        lowestGradeFound = myNodes[i].getGrade();
        pFristNode->reassasignNode(myNodes[i].getFristName(),
                myNodes[i].getLastName(), myNodes[i].getId(),
                myNodes[i].getGrade());
        cout << "int reassassigned" << endl;
    }

给我这个错误：

1 [main] Project 972 exception::handle: Exception: STATUS_ACCESS_VIOLATION 
2130 [main] Project 972 open_stackdumpfile: Dumping stack trace to Project.exe.stackdump

以及如何解决它的想法？

（抱歉，我留在诊断打印报表中。）

这也是影响myNodes的唯一代码：

vector<Node> Students;
Node node1("Bobby", "zilch",28,55);
Node node2("Evil", "Dentist",308,55);
Node node3("Raz", "Buton",10,55);
Students.push_back(node1);
Students.push_back(node2);
Students.push_back(node3);

cout<<"stuff"<<endl;
 LinkedListByGrade myList = LinkedListByGrade(Students);

Answer 1

我不能肯定地说，但是您正在访问未分配给您的内存，因此您可能正在myNodes的边界上运行。您将能够使用您的调试器来确定此。

我可以肯定地说，在你的功能的第一行，你打电话：

int lowestGradeFound = myNodes[0].getGrade();

如果myNodes中没有项目，则会导致访问冲突。

由于您正在访问myNodes，因此您肯定会在for循环中myNodes[myNodes.size()]结束。

尝试这样的事情：

LinkedListByGrade::LinkedListByGrade(vector<Node> const& myNodes) { // Pass by const-reference! ------------------^ // Set this to something high. Don't access the vector, in case there are no // elements therein: int lowestGradeFound = std::numeric_limits<int>::max(); // Where is this deleted? Node *pFirstNode = new Node(); // Use iterators, not indices for looping over a container... for (vector<Node>::iterator i = myNodes.begin(), end = myNodes.end(); != end; ++i) { // Access element by `i->` if (i->getGrade() < lowestGradeFound) { // Now you can assign this safely... lowestGradeFound = i->getGrade(); pFirstNode->reassasignNode( i->getFirstName(), i->getLastName(), i->getId(), i->getGrade()); } } // [...] }

但你真的，真的需要学会使用你的调试器！

1 [main] 972 exception :: handle：异常：STATUS_ACCESS_VIOLATION说明以及如何修复

1 个答案: