這就是我試圖解決的問(wèn)題：給定：一個(gè)包含名稱(chēng)哈希的數(shù)組Return：格式為用逗號(hào)分隔的名稱(chēng)列表的字符串，但最后兩個(gè)名稱(chēng)除外，最后兩個(gè)名稱(chēng)應(yīng)以 & 符號(hào)分隔。例：list([ {name: 'Bart'}, {name: 'Lisa'}, {name: 'Maggie'} ])// returns 'Bart, Lisa & Maggie'list([ {name: 'Bart'}, {name: 'Lisa'} ])// returns 'Bart & Lisa'list([ {name: 'Bart'} ])// returns 'Bart'list([])// returns ''注意：所有哈希值都經(jīng)過(guò)預(yù)先驗(yàn)證，并且僅包含 A-Z、a-z、“-”和 “。這是我的代碼：var finalName;var notFinal;function list(names){  var finalNames = names.forEach(returnNames);        console.log(typeof finalNames);  function returnNames() {    for (var i = 0; i<names.length; i++) {      var nameValue = Object.keys(names[i]).map(key => names[i][key])    }  }  for(var i = 0; i<finalNames.length; i++) {    if (finalNames.length / i == 1) {      finalName = "& " + finalNames[i];     }    else {      notFinal = finalNames[i] + ", ";    }  }  console.log(notFinal + finalName);}list([{name: 'Bart'},{name: 'Lisa'},{name: 'Maggie'},{name: 'Homer'},{name: 'Marge'}])它卡在循環(huán)中，最后給出一個(gè)錯(cuò)誤：TypeError: Cannot read property 'length' of undefined    at list    at /home/codewarrior/index.js:30:1    at Object.handleError        <anonymous>如何修復(fù)此問(wèn)題？