Combine values and keys to form json object

Question

I have the keys and values as strings and i need to combine those into a json format.

For example : my "keys" string array is : {"a","b","c","d"} my "values" string array i am getting through a for loop as it is stored in array X

X[0], X[1], X[2] and so on..

how do i combine "keys" and "values" to look like this:

{ "a":"x","b":"y", "c":"z", "d":"q"
}

I have tried iterating and combining but I'm stuck

std::string values="";
std::string keys[4]={"a","b","c","d"};
..
..
..
for(int i=0;i<4;i++)
{
    values= values + "," + x[i];
}

I'm confused as to how do i combine these two strings and display a resultant string that looks like this:

{ "a":"x",
  "b":"y",
  "c":"z",
  "d":"q"
}

Answer 1

Manual way can be done like:

std::string res = "{";
std::string keys[4]={"a","b","c","d"};
std::string values[4]={"a","b","c","d"};
const char* sep = "";

for(int i=0;i<4;i++)
{
    res += sep + keys[i] + ":" + values[i];
    sep = ",";
}
res += "}";

Using any json library, you might do something like:

Json::Value root(Json::ValueType::objectValue);

for (int i = 0; i < 4; i++) {
    root[keys[i]] = values[i];
}

Json::StyledWriter writer;
writer.write(root);