define a named variable in a function call

Question

What is the problem int the code? I've got:

"error: expected primary-expression before 'j'"

#include <vector>
using namespace std;

void foo(vector<int>& v){  
}

int main()
{
   foo( vector<int> j);
   return 0;
}

Answer 1

This is invalid:

foo( vector<int> j);

because you just can NOT define a named variable in a function call....

you mean for sure

int main()
{
    vector<int> j;
    foo(j);
    return 0;
}