表达式必须具有指向对象的指针类型（指针向量）

Question

In my function Delete I have an error that says that getTableColumns must have a pointer-to-object type.

Class Column is an abstract class.

class Table {

    vector<Column*> _columns;
    Column* value;
    char* name;
public:
    vector<Column*> getTableColumns() {
        return _columns;
    }

void Delete(char* name, int columnNumber, string thisValue) {
    for (int i = 0; i <= findLongestColumn(); i++) {
                if ((string)thisValue.compare((string)(getTableColumns()
                     [columnNumber]->getColumnValues()[i])) == 0)//!!!error
                {...}    
        }
}

template <typename T>
class DataColumn : public Column {

    vector<T> values;

public:
    void getColumnValues()
    {
        return values;
    }

Answer 1

Column::getColumnValues声明为void但您返回一个值，然后在结果中进行索引。