二维数组使用includes无效（cannot read property 'include

Question

程序的目的是arr[i][1]（也就是字符串）去重，并把去重后的结果插入result内，并返回，我的代码如下：

var arr = [ [ 88, 'Bowling Ball' ],

  [ 2, 'Dirty Sock' ],

  [ 3, 'Hair Pin' ],

  [ 12, 'Toothpaste' ],

  [ 2, 'Hair Pin' ],

  [ 3, 'Half-Eaten Apple' ],

  [ 7, 'Toothpaste' ],

  [ 2, 'Hair Pin' ],

  [ 3, 'Half-Eaten Apple' ],

  [ 67, 'Bowling Ball' ],

  [ 7, 'Toothpaste' ],

  [ 3, 'Half-Eaten Apple' ],

  [ 67, 'Bowling Ball' ],

  [ 7, 'Toothpaste' ],

  [ 2, 'Hair Pin' ],

  [ 3, 'Half-Eaten Apple' ],

  [ 67, 'Bowling Ball' ] ];

var result = [[0,'test']];

arr.forEach(function(e,i){

  

  if(!result[i].includes(e[1])){

    result.push(e);

  }

  

});

  

console.log(result);

可是在调试的时候，系统给我的反馈是：TypeError: Cannot read property 'includes' of undefined

我不是很明白，因为result[i]也应该是一个数组才对啊，怎么会出现这种情况呢？

求大神解答，谢谢。

Answer 1

!result[i].includes(e[1])大哥，你这result在位置0后边都是undefined了，当然TypeError: Cannot read property 'includes' of undefined