Question

我得到了关注而无法弄明白。任何一点。

#include<iostream>
#include<string>
#include<vector>
using namespace std;
typedef std::vector<std::string> fom_header;
typedef std::vector<fom_header> fom_data;

void print_data(fom_data &f)
{
    vector<fom_header>::iterator _header;
    vector<string>::iterator _data;
    for(_header = f.begin(); _header != f.end(); _header++)
    {
        for(_data = _header->begin(); _data != _header->end(); _data++)
        {
            cout<<"data ..."<<*_data;
        }
    }
}


int main()
{
    fom_header.push_back("A");
    fom_header.push_back("10");
    fom_header.push_back("20");
    fom_header.push_back("30");
    fom_data.push_back(fom_header);

    fom_header.push_back("B");
    fom_header.push_back("30");
    fom_header.push_back("40");
    fom_header.push_back("50");
    fom_data.push_back(fom_header);

    print_data(fom_data);

}

错误

create_2d.cpp:24:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:25:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:26:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:27:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:28:13: error: expected unqualified-id before ‘.’ token
create_2d.cpp:30:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:31:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:32:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:33:15: error: expected unqualified-id before ‘.’ token
create_2d.cpp:34:13: error: expected unqualified-id before ‘.’ token
create_2d.cpp:36:24: error: expected primary-expression before ‘)’ token

Answer 1

fom_header是一种类型。您需要该类型的实例：

fom_header hdr;
hdr.push_back("hello");

同样适用于fom_data。

Answer 2

fom_header这里只是一个类型，而不是vector<string>变量。您需要在调用push_back()之前定义此类型的变量（并且您需要对fom_data执行类似的操作）：

fom_header fom;
fom.push_back("A");

在向量中的'。'标记之前预期的nonqualified-id

2 个答案: