这是我用来获得两个数组之间的差异的函数-它适用于数值，字符串，混合num/字符串数组。在数组/多维数组中不是对象文字

function diff(arr1, arr2) {

    var x, 
        t;

    function uniq(a, b) {
        t = b;

        if( (b === 0 && x[b+1]!==a) || 
           (t > 0 && a !== x[b+1] && a !== x[b-1]) ) {
            return  a;
        }
    }


    x = arr1.concat(arr2).sort();

    return x.filter(uniq);
}

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

diff(a1, a2);

为了获得对称差异，您需要以两种方式比较数组(或在多个数组的情况下以所有方式比较)

ES7 (ECMAScript 2016)

// diff between just two arrays:
function arrayDiff(a, b) {
    return [
        ...a.filter(x => !b.includes(x)),
        ...b.filter(x => !a.includes(x))
    ];
}

// diff between multiple arrays:
function arrayDiff(...arrays) {
    return [].concat(...arrays.map( (arr, i) => {
        const others = arrays.slice(0);
        others.splice(i, 1);
        const unique = [...new Set([].concat(...others))];
        return arr.filter(x => !unique.includes(x));
    }));
}

ES6(2015年ECMAScript)

// diff between just two arrays:
function arrayDiff(a, b) {
    return [
        ...a.filter(x => b.indexOf(x) === -1),
        ...b.filter(x => a.indexOf(x) === -1)
    ];
}

// diff between multiple arrays:
function arrayDiff(...arrays) {
    return [].concat(...arrays.map( (arr, i) => {
        const others = arrays.slice(0);
        others.splice(i, 1);
        const unique = [...new Set([].concat(...others))];
        return arr.filter(x => unique.indexOf(x) === -1);
    }));
}

ES5 (ECMAScript 5.1)

// diff between just two arrays:
function arrayDiff(a, b) {
    var arrays = Array.prototype.slice.call(arguments);
    var diff = [];

    arrays.forEach(function(arr, i) {
        var other = i === 1 ? a : b;
        arr.forEach(function(x) {
            if (other.indexOf(x) === -1) {
                diff.push(x);
            }
        });
    })

    return diff;
}

// diff between multiple arrays:
function arrayDiff() {
    var arrays = Array.prototype.slice.call(arguments);
    var diff = [];

    arrays.forEach(function(arr, i) {
        var others = arrays.slice(0);
        others.splice(i, 1);
        var otherValues = Array.prototype.concat.apply([], others);
        var unique = otherValues.filter(function (x, j) { 
            return otherValues.indexOf(x) === j; 
        });
        diff = diff.concat(arr.filter(x => unique.indexOf(x) === -1));
    });
    return diff;
}

例子:

// diff between two arrays:
const a = ['a', 'd', 'e'];
const b = ['a', 'b', 'c', 'd'];
arrayDiff(a, b); // (3) ["e", "b", "c"]

// diff between multiple arrays
const a = ['b', 'c', 'd', 'e', 'g'];
const b = ['a', 'b'];
const c = ['a', 'e', 'f'];
arrayDiff(a, b, c); // (4) ["c", "d", "g", "f"]

对象数组之间的差异

function arrayDiffByKey(key, ...arrays) {
    return [].concat(...arrays.map( (arr, i) => {
        const others = arrays.slice(0);
        others.splice(i, 1);
        const unique = [...new Set([].concat(...others))];
        return arr.filter( x =>
            !unique.some(y => x[key] === y[key])
        );
    }));
}

例子:

const a = [{k:1}, {k:2}, {k:3}];
const b = [{k:1}, {k:4}, {k:5}, {k:6}];
const c = [{k:3}, {k:5}, {k:7}];
arrayDiffByKey('k', a, b, c); // (4) [{k:2}, {k:4}, {k:6}, {k:7}]

所选的答案只对了一半。您必须比较数组的两种方式才能得到完整的答案。

const ids_exist = [
   '1234',
   '5678',
   'abcd',
]

const ids_new = [
  '1234',
  '5678',
  'efjk',
  '9999',
]

function __uniq_Filter (__array_1, __array_2) {
  const one_not_in_two = __array_1.filter(function (obj) {
    return __array_2.indexOf(obj) == -1
  })
  const two_not_in_one = __array_2.filter(function (obj) {
    return __array_1.indexOf(obj) == -1
  })
  return one_not_in_two.concat(two_not_in_one)
}

let uniq_filter = __uniq_Filter(ids_exist, ids_new)

console.log('uniq_filter', uniq_filter) // => [ 'abcd', 'efjk', '9999' ]

ES6中一个更简洁的方法是以下解决方案。

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

区别

a2.filter(d => !a1.includes(d)) // gives ["c", "d"]

十字路口

a2.filter(d => a1.includes(d)) // gives ["a", "b"]

析取联合(对称差分)

[ ...a2.filter(d => !a1.includes(d)),
  ...a1.filter(d => !a2.includes(d)) ]

const difference = function (baseArray, arrayToCampare, callback = (a, b) => a!== b) {
  if (!(arrayToCampare instanceof Array)) {
    return baseArray;
  }
  return baseArray.filter(baseEl =>
    arrayToCampare.every(compareEl => callback(baseEl, compareEl)));
}

function diffArray(newArr, oldArr) {
    var newSet = new Set(newArr)
    var diff = []
    oldArr.forEach((a) => {
        if(!newSet.delete(a))diff.push(a)
    })
    return diff.concat(Array.from(newSet)) 
}