C++遍历Lua table的方法实例

lua table数据如下：

--$ 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",
                },
            },
        }

要读出上面table 中所有数据,c++代码如下：

//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;
}

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