我代码写的不好。

不过求差集好像filter一下就可以了。

var a = generateRandomArray(5, 10); var b = generateRandomArray(10, 10); // 不去重 var result = { a: a.filter(el => !b.includes(el)), b: b.filter(el => !a.includes(el)) } // 去重 var result2 = { a: [...new Set(a)].filter(el => !b.includes(el)), b: [...new Set(b)].filter(el => !a.includes(el)) } // 合并一下 function diffSet(a, b, noDup) { if (noDup) { a = [...new Set(a)]; b = [...new Set(b)]; } return { a: a.filter(el => !b.includes(el)), b: b.filter(el => !a.includes(el)) } }

至于对象数组。。。太麻烦了，等你先把这个看明白了再说：lodash.isEqual

---

不使用ES6:

// 不去重 // 使用indexOf代替includes a.filter(function(el){ return b.indexOf(el) == -1; }); // 去重 // 引入index先对a自身去重 a.filter(function(el, idx){ return a.indexOf(el) == idx && b.indexOf(el) == -1; });

新方法：

/** * 新方法 * @param {Object} a * @param {Object} b * @param {Object} isDup 是否不去重（默认去重） */ function arrayDiffSet(a, b, isDup) { var al = a.length, bl = b.length; if ((!a || !al) && (b && bl)) { return b } else if ((!b || !bl) && (a && al)) { return a } var i = 0, aMap = {}, _aMap = {}, _bMap = {}, _a = [], _b = [], temp; for (i = 0; i < al; i++) { temp = a[i]; aMap[temp] = true; !_aMap[temp] ? _aMap[temp] = [] : ''; _aMap[temp][_aMap[temp].length] = temp; } for (i = 0; i < bl; i++) { temp = b[i]; if (aMap[temp]) { delete _aMap[temp]; } else { _b[_b.length] = temp; _bMap[temp] = true; } } if (isDup) { for (var item in _aMap) { _a = _a.concat(_aMap[item]); } return { a: _a, b: _b } } return { a: Object.keys(_aMap), b: Object.keys(_bMap) } } function generateRandomArray(length, range) { var result = []; for (var i = 0; i < length; i++) { result[result.length] = Math.floor(Math.random() * range); } return result } var a = generateRandomArray(1000, 1000); var b = generateRandomArray(1000, 1000); console.log(a); console.log(b); console.time('start'); console.log(arrayDiffSet(a, b, true)); console.timeEnd('start');

另附：jQuery也是可以去重的
var a = [1, 2, 3, 4];
var b = [1, 2, 4, 5];
var c = $(a).not(b);
c = c.toArray(); // [3]