process.stdin.resume();
process.stdin.setEncoding('utf8');

const Equipment = [
{name: "剣", value: "どうのつるぎ"},
{name: "防具", value: "かわのたて"},
{name: "防止", value: "かわのぼうし"},
{name: "ナイフ", value: "ブロンズナイフ"}
];

data = Equipment.reduce(function(p,c){
        if(p[c['name']] === undefined){
          p[c['name']] = [];
        }
        p[c['name']].push(c['value']|0);
            return p;
}, {});

console.log(data);

結果 ⇛ 連想配列になる

{
  '剣': [ 'どうのつるぎ' ],
  '防具': [ 'かわのたて' ],
  '防止': [ 'かわのぼうし' ],
  'ナイフ': [ 'ブロンズナイフ' ]
}

var player ={name: "Ronaldo", team: "Juventus"};

player.uniNumber = 7;

console.log(player);