javascript - javascript 中数组末尾的未知元素？

Question

我对 JavaScript 比较陌生，所以请饶了我吧。在解决 Freecodecamp 的其中一个问题时，需要在两个数组中找到唯一值。我写了一小段代码。

它适用于仅包含整数的数组。比较字符串数组时会出现问题。尾随元素被添加到最终输出数组，它甚至不可见。它应该只为这段代码输出一个值。

像这样。

"[*] Total unique values found = 2"
"[*] Unique values = pink wool,"

这是代码。它被混淆了。

function diffArray(arr1, arr2) {
  var newArr = [];
  var length1 = arr1.length;
  var length2 = arr2.length;
  var test = true;
  var tab = '     ';
  console.log('[*] Starting ... '+tab);

  while(arr1.length > 0 && arr2.length > 0 ) 
  {
    console.log('[*] Entering while loop.');
reset:
    for (var i=0; i<arr2.length; i++) 
    {
      console.log('[*] Comparing '+arr1[0]+' and '+arr2[i]);
      if(arr1[0] == arr2[i]) 
      {
        console.log('[*] Matched ... ')
        console.log('   $ Removig '+arr1[0]+' from arr1 and arr2');
        arr1.splice(0, 1);
        arr2.splice(i, 1);
        console.log("   $ arr1 length = "+arr1.length);
        console.log("   $ arr2 length = "+arr2.length);
        break reset;
      } else if (i == arr2.length-1) 
      {
        console.log("   $ No match found.");
        console.log('[*] Pushing '+arr1[0]+' in newArr');
        newArr.push(arr1[0]);
        arr1.splice(0, 1);

        console.log('[*} newArr = '+newArr);
      } else {
        console.log('[*] Match failed.')
      }
    }
  }

  if(arr2.length > 0) {
    newArr.push(arr2);
  } else {
    newArr.push(arr1);
  }
 console.log('[*] Total unique values found = '+newArr.length);
 console.log('[*] Unique values = '+newArr);
}

diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]);

这里是 JSBin 的链接有工作示例。

这里是 JSBin 的链接字符串数组不起作用..

感谢您的帮助。

Answer 1

只是连接和过滤 double

var diffArray = (arr1, arr2) => arr1.concat(arr2).filter((x,i,arr) => arr.indexOf(x) === arr.lastIndexOf(x));

var res = diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]);

console.log(res);

在旧的 javascript 中:

function diffArray(arr1, arr2) {
   return arr1.concat(arr2).filter(function(x,i,arr) { 
       return arr.indexOf(x) === arr.lastIndexOf(x)
   })
}