javascript - i 没有在 while 循环中定义

Question

我正在尝试添加匹配数组的所有数字并删除重复的名称。它适用于第一个实例，但 while 循环不会越过 Apples。

function updateInventory(arr1, arr2) {

   function alphabetizer(a, b) {
   if (a[1] < b[1]) return -1;
   if (a[1] > b[1]) return 1;
   return 0;
   }

  var newInv = arr1.concat(arr2).sort(alphabetizer);


  for(var i = 0; i < newInv.length; i++) {
    while(newInv[i][1] === newInv[i++][1]) {
      newInv[i] += newInv[i++][0];
      newInv.push([newInv[i][0], newInv[i][1]]);
      newInv.splice(i,2);


   }
  } 

    return newInv;
}

// Example inventory lists
var curInv = [
    [21, "Bowling Ball"],
    [2, "Dirty Sock"],
    [1, "Hair Pin"],
    [5, "Microphone"],
    [10, "Apples"]
];

var newInv = [
    [9, "Apples"],
    [2, "Hair Pin"],
    [3, "Half-Eaten Apple"],
    [67, "Bowling Ball"],
    [7, "Toothpaste"]
];

updateInventory(curInv, newInv);

它一直给我错误 TypeError: newInv[(+ i)] is undefined 但我不确定为什么，因为 i 已定义，并且如果我只是尝试运行 newInv[ i] 我得到第一个结果。

JS Fiddle link

Answer 1

有几个地方需要修复。我更新了这个 jsfiddle

function updateInventory(arr1, arr2) {

    function alphabetizer(a, b) {
        if (a[1] < b[1]) return -1;
        if (a[1] > b[1]) return 1;

        return 0;    
    }

    var newInv = arr1.concat(arr2).sort(alphabetizer);

    for (var i = 0; i < newInv.length; i++) {
        var j = i;
        while (newInv[j + 1] && newInv[j][1] == newInv[j + 1][1]) {
            newInv[j][0] += newInv[j + 1][0];
            newInv.splice(j + 1, 1);
            j++;
        }
    }

    document.getElementById('test').innerHTML = newInv.join('<br>');
}

// Example inventory lists
var curInv = [
    [21, "Bowling Ball"],
    [2, "Dirty Sock"],
    [1, "Hair Pin"],
    [5, "Microphone"],
    [10, "Apples"]
];

var newInv = [
    [9, "Apples"],
    [2, "Hair Pin"],
    [3, "Half-Eaten Apple"],
    [67, "Bowling Ball"],
    [7, "Toothpaste"]
];

updateInventory(curInv, newInv);

https://jsfiddle.net/c3j8p2zu/7/