Question

Currently I have a map that prints out the following

map<string, map<int,int> > mapper;
map<int,int>::iterator inner;
map<string, map<int,int> >::iterator outer;


for(outer = mapper.begin(); outer != mapper.end(); outer++){
    cout<<outer->first<<": ";
  for(inner = outer->second.begin(); inner != outer->second.end(); inner++){
      cout<<inner->first<<","<<inner->second<<",";
  }
}

As of now this prints out the following

  stringone: 1,2,3,4,6,7,8,
  stringtwo: 3,5,6,7,
  stringthree: 2,3,4,5,

What i want it to print out is

  stringone: 1,2,3,4,6,7,8
  stringtwo: 3,5,6,7
  stringthree: 2,3,4,5

how can i check for the end of the map inside my inner map?
Any help would be appreciated Thank you

Answer 1

Change your output line to print the comma first and only if it is not the first element:

if (inner != outer->second.begin())
    std::cout << ",";
std::cout << inner->first << "," << inner->second;