when i try to compile i keep getting message vector subscript out of range - c++

Question

string getName() { return name; }
string getE1() { return enemy1; }
string getE2() { return enemy2; }
string getE3() { return enemy3; }
bool isEnemy(string check) {
if (check == enemy1 || check == enemy2 || check == enemy3)
//if the name being checked is an enemy of this knight
return true;
else
return false;
}
int Candidate(Knight b) {//'b' is an enemy of 'a' who is in the seat before 'b'(ie. b seat=2 a seat=1
int toSwap = b.seatingPos;//toSwap holds seating pos # of 'b'
int checkFriends = (toSwap - 1);//holds seating pos of 'a'
string nameA = table[checkFriends].getName();
for (int i = 0; i < 8; i++) {
if (table[i].isEnemy(nameA) || table[i].getName() == nameA) //if not enemies, then must be friends
{
continue;
}
else
{
friends.push_back(table[i].seatingPos);
}//adds seating # of friends of 'a' to friends vector
}
for (int j = 0; j < 4; j++) {//check friends of 'a' to see if their neighbor is friends with 'b'
int check2 = table[friends[j]].seatingPos;//check 2 holds seating pos # of 'c'
if (check2 != 7)
++check2;
else
return check2;
if ((table[toSwap].isEnemy(table[check2].getName()))) //if neighbor of c is friends with b(toSwap)
{
continue;
}
else {
return check2;//if not enemies then must be friends return seating pos of acceptable candidate
}
}
return 0;
}
when i debug the code it says i have an unhandled exception when assigning
string nameA = table[checkFriends].getName();
the value of checkfriends = 0 so it shouldnt be out of the range of the vector.
debugger also says: Unhandled exception at 0x7BC8F2F6 (ucrtbased.dll) in Knights.exe: An invalid parameter was passed to a function that considers invalid parameters fatal. occurred
this occurs during the 1st if statement.
thanks for any help!!!