javascript - While 循环在第一次迭代时停止

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(i=0;i<newInv.length;i++){

    while(newInv[i][1] != -1){
      newInv[i][0] += newInv[i+1][0];
      newInv.push([newInv[i][0], newInv[i][1]]);
      newInv.splice(i,2);
      return newInv;
    }
    return newInv;
  }

    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);

所以当我运行这个时，我最终得到了

[[21,"Bowling Ball"],[67,"Bowling Ball"],[2,"Dirty Sock"],[1,"Hair Pin"],[2,"Hair Pin"],[3,"Half-Eaten Apple"],[5,"Microphone"],[7,"Toothpaste"],[19,"Apples"]]

Answer 1

问题是因为您正在从 while 循环返回。它终止循环的进一步执行。从 for 和 while 循环中删除 return 部分。并且还使用 var 关键字声明变量 i，以使其作用域限于函数，而不是全局。

for(var i = 0; i < newInv.length; i++) {

    while(newInv[i][1] != -1) {

      newInv[i][0] += newInv[i+1][0];
      newInv.push([newInv[i][0], newInv[i][1]]);
      newInv.splice(i,2);

    }

}