是否有一种方法可以在JavaScript中返回两个数组之间的差异?

例如:

var a1 = ['a', 'b'];
var a2 = ['a', 'b', 'c', 'd'];

// need ["c", "d"]

当前回答

Array.prototype.diff =函数(a) { return this.filter(function(i) {return a.f index_of (i) < 0;}); }; ////////////// //示例// ////////////// Const dif1 =[1,2,3,4,5,6]。Diff ([3,4,5]); console.log (dif1);// => [1,2,6] const dif2 =[“test1”、“test2”,“test3”,“test4”,“test5”,“test6”].diff([“test1”、“test2”,“test3”、“test4”)); console.log (dif2);// => ["test5", "test6"]

注意:. indexof()和.filter()在IE9之前是不可用的。

其他回答

Samuel:“对于我的代码,我也需要删除副本,但我想这并不总是可取的。 我想主要的缺点是它可能会比较许多已经被拒绝的选择。”

当比较TWO列表、数组等,且元素小于1000时,行业标准中的 3GL世界是使用冒泡排序,以避免欺骗。

代码看起来像这样……(未经测试,但应该有效)

var Array01=new Array('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P');
var Array02=new Array('X','B','F','W','Z','X','J','P','P','O','E','N','Q');
var Array03=Array01;

for(x=1; x<Array02.length; x++) {
 for(y=0; y<Array01.length-1; y++) {
  if (Array01[y]==Array02[x]) {Array03.splice(y,1);}}}

Array01=Array03;

要测试输出…

for(y=0; y<Array01.length; y++) {document.write(Array01[y])}
function array_diff(array1, array2) {
   let returnArray = [];
   $.each(array1, function(index, value) {
     let findStatus = false;
     if (Array.isArray(array2)) {
       $.each(array2, function(index2, value2) {
         if (value == value2) findStatus = true;
       });
     } else {
       if (value == array2) {
         findStatus = true;
       }
     }

     if (findStatus == false) {
       returnArray.push(value);
     }
   });
   return returnArray;
}

下面是另一个可以返回差异的解决方案,就像git diff一样:(它已经用typescript编写,如果你不使用typescript版本,只需删除类型)

/**
 * util function to calculate the difference between two arrays (pay attention to 'from' and 'to'),
 * it would return the mutations from 'from' to 'to' 
 * @param { T[] } from
 * @param { T[] } to
 * @returns { { [x in string]: boolean } } it would return the stringified version of array element, true means added,
 * false means removed
 */
export function arrDiff<T>(from: T[], to: T[]): { [x in string]: boolean } {

  var diff: { [x in string]: boolean } = {};
  var newItems: T[] = []
  diff = from.reduce((a, e) => ({ ...a, [JSON.stringify(e)]: true }), {})

  for (var i = 0; i < to.length; i++) {
    if (diff[JSON.stringify(to[i])]) {
      delete diff[JSON.stringify(to[i])]
    } else {
      newItems.push(to[i])
    }
  }

  return {
    ...Object.keys(diff).reduce((a, e) => ({ ...a, [e]: false }), {}),
    ...newItems.reduce((a, e) => ({ ...a, [JSON.stringify(e)]: true }), {})
  }
}

下面是一个用法示例:

arrDiff(['a', 'b', 'c'], ['a', 'd', 'c', 'f']) //{"b": false, "d": true, "f": true}

这是工作的:基本上合并两个数组,寻找重复的,并将没有重复的推入一个新数组,这是差异。

函数diff(arr1, arr2) { var newArr = []; Var arr = ar1 .concat(arr2); For (var I in arr){ Var f = arr[i]; Var t = 0; (j = 0;j < arr.length;j + +) { If (arr[j] === f){ t + +; } } 如果(t == 1){ newArr.push (f); } } 返回newArr; }

function diffArray(arr1, arr2) {
  const newArr = [];

// arr1 match to arr2
arr1.map((item)=>{
if(arr2.indexOf(item)<0){
  console.log(item)
  newArr.push(item)
}  
})

// arr2 match to arr1
arr2.map((item)=>{
if(arr1.indexOf(item)<0){
  newArr.push(item)
}
})

  return newArr; 
}

差异([1,2,3,5],[1,2,3,4,5])

输出::[4]