vector of list of string in cpp, “EXC_BAD_ACCESS”

Question

#include <iostream>
#include <vector>
#include <list>
using namespace std;
int main()
{
    vector<list<string> > testList;
    testList[2].push_back("ADA");
    return 0;
}

It got a thread, when program running. signal: "EXC_BAD_ACCESS"

I guesse it's because of illegal memory access, but I don't know why and how to fix it.

thanks so much

Answer 1

testList has length 0 after initialization, therefore you cannot access testList[2] .

You can pass an initial size to the c'tor of std::vector, so the following should work

vector<list<string> > testList(3);
testList[2].push_back("ADA");

Answer 2

您的testList大小为0，因此您无法访问元素2.因为您需要调整它的大小：

testList.resize(3);