c++ 遍历lua table方法 如图

//C++代码：

#include <lua.hpp>

#include <iostream>

#include <string>

using namespace std

bool popTable(lua_State* L, int idx)

{

    try{

        lua_pushnil(L)

        while(lua_next(L, idx) != 0){

            int keyType = lua_type(L, -2)

            if(keyType == LUA_TNUMBER){

                double value = lua_tonumber(L, -2)

                cout << "Key:" << value << endl

            }else if(keyType == LUA_TSTRING){

                const char*  value = lua_tostring(L, -2)

                cout << "Key:" << value << endl

            }else{

                cout << "Invalid key type: " << keyType << endl

                return false

            }

            int valueType = lua_type(L, -1)

            switch(valueType){

                case LUA_TNIL:

                {

                    cout << "Value: nil" << endl

                    break

                }

                case LUA_TBOOLEAN:

                {

                    int value = lua_toboolean(L, -1)

                    cout << value << endl

                    break

                }

                case LUA_TNUMBER:

                {    cout << "Value:" << lua_tonumber(L, -1) << endl

                    break

                }

                case LUA_TSTRING:

                {

                    cout << "Value:" << lua_tostring(L, -1) << endl

                    break

                }

                case LUA_TTABLE:

                {

                    cout << "====sub table===" << endl

                    int index = lua_gettop(L)

                    if (!popTable(L, index)) {

                        cout << "popTable error in  popTable,error occured" << endl

                        return false

                    }

                    break

                }

                default:

                {

                    cout << "Invalid value type: " << valueType << endl

                    return false

                }

            }

            lua_pop(L, 1)

        }

    }catch(const char* s){

       string errMsg = s

       lua_pop(L,1)

       cout << errMsg << endl

       return false

    }catch(std::exception& e){

        const char* errMsg = e.what()

        lua_pop(L,1)

        cout << errMsg << endl

        return false

    }catch(...){

        const char* errMsg = lua_tostring(L,-1)

        lua_pop(L,1)

        cout << errMsg << endl

        return false

    }

    return true

}

int main(int argc, char* argv)

{

    lua_State* L = luaL_newstate()

    luaL_openlibs(L)

    int r = luaL_dofile(L,"./test.lua")

    lua_getglobal(L, "user")

    int type = lua_type(L,1)

    if(type == LUA_TTABLE){

        int index = lua_gettop(L)

        if(popTable(L,index)){

            return 0

        }else{

            cout << "Error" << endl

            return -1

        }

    }

    return 0

} --$ cat test.lua lua文件 

user = {

["name"] = "zhangsan",

["age"] = "22",

["friend"] = {

[1] = {

["name"] = "小丽",

["sex"] = "女",

["age"] = "20",

},

[2] = {

["name"] = "小罗",

["sex"] = "男",

["age"] = "20",

},

},

}

运行结果：

$ ./cpptable.linux_64_gcc4

Key:age

Value:22

Key:name

Value:zhangsan

Key:friend

====sub table===

Key:2

====sub table===

Key:sex

Value:男

Key:age

Value:20

Key:name

Value:小罗

Key:1

====sub table===

Key:sex

Value:女

Key:age

Value:20

Key:name

Value:小丽

require "luasql.mysql"

env = assert (luasql.mysql())

con = assert (env:connect"my_db")

for b (con, "select a from b") do

print (string.format ("%s", b))

end

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