Some coding challenges for the AO front end team who are learning JavaScript

Format a bunch of football results

// take a bunch of football results from this object 
// and return an array of results summaries including teams competing, score and scorers

var results = {
    "02-01-2016" : {
        results : [{
            teamA : {
                name : "Manchester United",
                goals : 2,
                scorers : ["Rooney", "Martial"],
                booked : ["Rooney", "DeGea", "Carrick"],
                sentOff : [],
                subs : [{ name : "Memphis", replaced : "Rooney", time : 82 }] 
            },
            teamB : {
                name : "Watford",
                goals : 0,
                scorers : [],
                booked : ["Ekstrand", "Deeney"],
                sentOff : [ { name : "Deeney", time : 57 }],
                subs : [
                    { name : "Johnson", replaced : "Britos", time : 58 }, 
                    { name : "Watson", replaced : "Behrami", time : 58 }
                ] 
            }
        }, {
            teamA : {
                name : "Liverpool",
                goals : 1,
                scorers : ["Sturridge"],
                booked : ["Allen"],
                sentOff : [],
                subs : [{ name : "Benteke", replaced : "Sturridge", time : 65 }] 
            },
            teamB : {
                name : "Chelsea",
                goals : 1,
                scorers : ["Costa", "Costa"],
                booked : ["Terry", "Costa", "Mikel"],
                sentOff : [ { name : "Costa", time : 67 }],
                subs : [{ name : "Mikel", replaced : "Willian", time : 71 }] 
            }
        }]
    },
    "03-01-2016" : {
        results : [{
            teamA : {
                name : "Manchester City",
                goals : 3,
                scorers : ["Aguero", "Aguero", "Aguero"],
                booked : ["Hart"],
                sentOff : [],
                subs : [{ name : "Bony", replaced : "Aguero", time : 70 }] 
            },
            teamB : {
                name : "Newcastle",
                goals : 0,
                scorers : [],
                booked : ["Collocini", "Cisse", "Perez"],
                sentOff : [ 
                    { name : "Collocini", time : 34 },
                    { name : "Krul", time : 55 }
                ],
                subs : [{ name : "Elliot", replaced : "Sissoko", time : 34 }] 
            }
        }, {
            teamA : {
                name : "Leicester",
                goals : 1,
                scorers : ["Vardy"],
                booked : [],
                sentOff : [],
                subs : [{ name : "Marrez", replaced : "Ulloa", time : 56 }] 
            },
            teamB : {
                name : "Arsenal",
                goals : 0,
                scorers : [],
                booked : ["Cech"],
                sentOff : [],
                subs : [
                    { name : "Ramsey", replaced : "Ozil", time : 71 },
                    { name : "Sanchez", replaced : "Giroud", time : 71 }
                ] 
            }
        }]
    }
};

function getResults(_results) {
  return Object.keys(_results)
    .map(key => _results[key].results)
    .reduce((arr, i) => arr.concat(i), [])
    .map(item => { return { 
        game : `${item.teamA.name} vs. ${item.teamB.name}`,
        score :  `${item.teamA.goals}-${item.teamB.goals}`,
        scorers : item.teamA.scorers.concat(item.teamB.scorers) 
    }});
}