[Programmers] (Javascript) 오픈채팅방

function solution(record) {
    var answer = [];
    var idName = new Map();
    var cmds = []

    for (const reco of record)
    {
        var data = reco.split(' ');
        var cmd = data[0];
        var id = data[1];
        if (cmd !== 'Change')
        {
           cmds.push([cmd,id]);    
        }

        if (data.length == 3)
        {
            idName.set(id, data[2]);
        }
    }

    for (const e of cmds)
    {
        if (e[0] === 'Enter'){
            answer.push(`${idName.get(e[1])}님이 들어왔습니다.`);
        }
        else{
            answer.push(`${idName.get(e[1])}님이 나갔습니다.`);
        }
    }
    return answer;
}