获取比较Javascript中两个或多个数组的Common和Uniques元素

Question

首先我查了很多帖子，像这样：

而且可能永远不会是数组中的重复值。用普通的JS会很棒

而且我不关心IE（但我想对其他人来说会很好），所以如果有一个新的ES6方式，我会喜欢它，我更关心性能：）

// Some values that gonna be inside the array1 & array2
function random(){};
var a = 5,
    b = {};


// The Arrays
var array1 = [0,1,2,3, "HeLLo", "hello", 55.32, 55.550, {key: "value", keyWithArray: [1,2,3]}, random, a, b];
var array2 = [2,3, "hello", "Hello", 55.32, 55.551, {key: "value", keyWithArray: [1,2,3]}, b];



// The Unique Array should be all the elements that array1 have and array2 haven't
var uniqueArray = [0, 1, "HeLLo", 55.550, random, a];


// The commonArray should the common elements in both arrays (array1 and array2)
var commonArray = [2,3, "hello", 55.32, {key: "value", keyWithArray: [1,2,3]}, b]




// I try something like this but doesn't work
var uniqueArray = array1.filter(function(val) { return array2.indexOf(val) == -1; });
console.log(uniqueArray);

Answer 1

根据我的理解，您基本上希望对两个数组执行一些set操作。我的建议是首先从两个数组中构建一个更合适的数据结构，因为要想获得这两个数组的交点，必须使用O(N²)算法。类似这样的事情应该可以做到：

// convert a plain array that has values of mixed types to and object
// where the keys are the values in plain form in case of strings, scalars or functions, or serialized objects in
// case of objects and arrays, and where the values are the unaltered values of the array.
var _toObject = function(arr) {
    var obj = {};
    for (var i=0 ; i<arr.length ; i++) {
        var el = arr[i];
        var type = typeof el;
        if (type !== 'object') { // scalars, strings and functions can be used as keys to an array
            obj[el] = el;
        }
        else { // objects and arrays have to be serialized in order to be used as keys
            obj[JSON.stringify(el)] = el;
        }
    };
    return obj;
};


var objArray1 = _toObject(array1);
var objArray2 = _toObject(array2);

var uniqueArray = [];
var commonArray = [];
for (var i in objArray1) {
    if (i in objArray2) {
        commonArray.push(objArray1[i]); // push the common elements

        delete objArray2[i]; // delete so in the end objArray2 will only have unique elements
    }
    else {
        uniqueArray.push(objArray1[i]); // push unique element from objArray1
    }
}

for (var i in objArray2) { // now objArray2 has only unique values, just append then to uniqueArray
    uniqueArray.push(objArray2[i])
}

console.log('Unique array', uniqueArray);
console.log('Common array', commonArray);

这应该会给出您想要的结果：

bash-4.2$ node test.js 
Unique array [ 0, 1, 5, 'HeLLo', 55.55, [Function: random], 'Hello', 55.551 ]
Common array [ 2, 3, 'hello', 55.32, { key: 'value', keyWithArray: [1, 2, 3 ] }, {}]