C++: How to implement (something like) JSON
Not sure how to explain it - I'm pretty new to C++, but... let me try:
Let's say I have 300+ names (Jeff, Jack...) with 300+ int values (0 or 1). In J开发者_Python百科S I would use JSON. Something like this:
var people = {"person": [
{"name": "Jeff","val": 0},
{"name": "Jill","val": 1},
{"name": "Jack","val": 0},
{"name": "Jim","val": 1},
{"name": "John","val": 0}
]}
What's the best way to do this in C++? Thanks.
If you can have duplicate names you can't use a map, so you could use something like this:
struct Person
{
Person( const std::string & n, int v ) : name(n), val(v) {}
std::string name;
int val;
};
int main()
{
std::vector<Person> people;
people.push_back( Person( "Jeff", 0 ) );
people.push_back( Person( "Jill", 1 ) );
...
}
If you wanted uniqueness of names you could do something like this:
std::map<std::string, int> people;
people["Jeff"] = 0;
people["Jill"] = 1;
or
std::map<std::string, Person> people;
people["Jeff"] = Person("Jeff",0);
people["Jill"] = Person("Jill",1);
If you're using this code a lot you can clean up the repeated cruft.
template<typename K, typename V>
struct BuildMap
{
BuildMap() : map_() {}
BuildMap<K,V>& operator()( const K & key, const V & value )
{
map_[key]=value;
return *this;
}
std::map<K,V> operator()() { return map_; }
std::map<K,V> map_;
};
std::map<std::string,int> people = BuildMap<std::string,int>()
( "Jeff", 0 )
( "Jill", 1 )
( "John", 1 )
();
Hope this gives you some ideas.
Take a look at jsoncpp - it is a lightweight json parser, that makes it very easy to use json in your c++ project.
http://sourceforge.net/projects/jsoncpp/
Then you can create a text file, write some entries in the json format there and then open this file in your c++ program. There are plenty of tutorials of how to do it with jsoncpp.
Try looking at std::map.
link here http://www.cplusplus.com/reference/stl/map/
It's an associative container that is similar to a dictionary. Something like this?
#include <map>
#include <string>
std::map<string,int> person;
void initPeople(){
person["Jeff"] = 0;
person["Jill"] = 1;
person["Jack"] = 0;
person["Jim"] = 1;
person["John"] = 0;
}
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