这是我使用的一个非常简单的实现。它是无损的，也确保不复制整个。

Array.prototype.contains = function(elem) {
    return(this.indexOf(elem) > -1);
};

Array.prototype.intersect = function( array ) {
    // this is naive--could use some optimization
    var result = [];
    for ( var i = 0; i < this.length; i++ ) {
        if ( array.contains(this[i]) && !result.contains(this[i]) )
            result.push( this[i] );
    }
    return result;
}

另一种可以同时处理任意数量数组的索引方法:

// Calculate intersection of multiple array or object values.
function intersect (arrList) {
    var arrLength = Object.keys(arrList).length;
        // (Also accepts regular objects as input)
    var index = {};
    for (var i in arrList) {
        for (var j in arrList[i]) {
            var v = arrList[i][j];
            if (index[v] === undefined) index[v] = 0;
            index[v]++;
        };
    };
    var retv = [];
    for (var i in index) {
        if (index[i] == arrLength) retv.push(i);
    };
    return retv;
};

它只适用于可以作为字符串计算的值，你应该将它们作为一个数组传递:

intersect ([arr1, arr2, arr3...]);

.．.但它透明地接受对象作为参数或任何要交叉的元素(总是返回公共值的数组)。例子:

intersect ({foo: [1, 2, 3, 4], bar: {a: 2, j:4}}); // [2, 4]
intersect ([{x: "hello", y: "world"}, ["hello", "user"]]); // ["hello"]

编辑:我只是注意到，这是，在某种程度上，有点bug。

也就是说:我在编码时认为输入数组本身不能包含重复(正如所提供的示例那样)。

但如果输入数组恰好包含重复，就会产生错误的结果。示例(使用下面的实现):

intersect ([[1, 3, 4, 6, 3], [1, 8, 99]]);
// Expected: [ '1' ]
// Actual: [ '1', '3' ]

幸运的是，这很容易通过添加二级索引来解决。那就是:

变化:

        if (index[v] === undefined) index[v] = 0;
        index[v]++;

by:

        if (index[v] === undefined) index[v] = {};
        index[v][i] = true; // Mark as present in i input.

,:

         if (index[i] == arrLength) retv.push(i);

by:

         if (Object.keys(index[i]).length == arrLength) retv.push(i);

完整的例子:

// Calculate intersection of multiple array or object values.
function intersect (arrList) {
    var arrLength = Object.keys(arrList).length;
        // (Also accepts regular objects as input)
    var index = {};
    for (var i in arrList) {
        for (var j in arrList[i]) {
            var v = arrList[i][j];
            if (index[v] === undefined) index[v] = {};
            index[v][i] = true; // Mark as present in i input.
        };
    };
    var retv = [];
    for (var i in index) {
        if (Object.keys(index[i]).length == arrLength) retv.push(i);
    };
    return retv;
};

intersect ([[1, 3, 4, 6, 3], [1, 8, 99]]); // [ '1' ]

如果你需要让它处理交叉多个数组:

Const intersect = (a1, a2，…rest) => { Const a12 = a1。过滤器(value => a2.includes(value)) 如果休息。长度=== 0){返回a12;｝ 回归相交(a12，…rest); }; console.log(相交([1、2、3、4、5],[1,2],[1、2、3、4、5],[2 10 1]))

我认为在内部使用一个对象可以帮助计算，也可以提高性能。

//方法维护每个元素的计数，也适用于负元素

function intersect(a,b){
    
    const A = {};
    a.forEach((v)=>{A[v] ? ++A[v] : A[v] = 1});
    const B = {};
    b.forEach((v)=>{B[v] ? ++B[v] : B[v] = 1});
    const C = {};
    Object.entries(A).map((x)=>C[x[0]] = Math.min(x[1],B[x[0]]))
    return Object.entries(C).map((x)=>Array(x[1]).fill(Number(x[0]))).flat();
}
const x = [1,1,-1,-1,0,0,2,2];
const y = [2,0,1,1,1,1,0,-1,-1,-1];
const result = intersect(x,y);
console.log(result);  // (7) [0, 0, 1, 1, 2, -1, -1]

该函数利用字典的强大功能，避免了N^2问题。每个数组只循环一次，第三次更短的循环返回最终结果。 它还支持数字、字符串和对象。

function array_intersect(array1, array2) 
{
    var mergedElems = {},
        result = [];

    // Returns a unique reference string for the type and value of the element
    function generateStrKey(elem) {
        var typeOfElem = typeof elem;
        if (typeOfElem === 'object') {
            typeOfElem += Object.prototype.toString.call(elem);
        }
        return [typeOfElem, elem.toString(), JSON.stringify(elem)].join('__');
    }

    array1.forEach(function(elem) {
        var key = generateStrKey(elem);
        if (!(key in mergedElems)) {
            mergedElems[key] = {elem: elem, inArray2: false};
        }
    });

    array2.forEach(function(elem) {
        var key = generateStrKey(elem);
        if (key in mergedElems) {
            mergedElems[key].inArray2 = true;
        }
    });

    Object.values(mergedElems).forEach(function(elem) {
        if (elem.inArray2) {
            result.push(elem.elem);
        }
    });

    return result;
}

如果有无法解决的特殊情况，仅通过修改generateStrKey函数就可以解决。这个函数的诀窍在于，它根据类型和值唯一地表示每个不同的数据。

这个变体有一些性能改进。在任何数组为空的情况下避免循环。它还首先遍历较短的数组，因此如果它在第二个数组中找到了第一个数组的所有值，则退出循环。

function array_intersect(array1, array2) 
{
    var mergedElems = {},
        result = [],
        firstArray, secondArray,
        firstN = 0, 
        secondN = 0;

    function generateStrKey(elem) {
        var typeOfElem = typeof elem;
        if (typeOfElem === 'object') {
            typeOfElem += Object.prototype.toString.call(elem);
        }
        return [typeOfElem, elem.toString(), JSON.stringify(elem)].join('__');
    }

    // Executes the loops only if both arrays have values
    if (array1.length && array2.length) 
    {
        // Begins with the shortest array to optimize the algorithm
        if (array1.length < array2.length) {
            firstArray = array1;
            secondArray = array2;
        } else {
            firstArray = array2;
            secondArray = array1;            
        }

        firstArray.forEach(function(elem) {
            var key = generateStrKey(elem);
            if (!(key in mergedElems)) {
                mergedElems[key] = {elem: elem, inArray2: false};
                // Increases the counter of unique values in the first array
                firstN++;
            }
        });

        secondArray.some(function(elem) {
            var key = generateStrKey(elem);
            if (key in mergedElems) {
                if (!mergedElems[key].inArray2) {
                    mergedElems[key].inArray2 = true;
                    // Increases the counter of matches
                    secondN++;
                    // If all elements of first array have coincidence, then exits the loop
                    return (secondN === firstN);
                }
            }
        });

        Object.values(mergedElems).forEach(function(elem) {
            if (elem.inArray2) {
                result.push(elem.elem);
            }
        });
    }

    return result;
}

function intersection(A,B){
var result = new Array();
for (i=0; i<A.length; i++) {
    for (j=0; j<B.length; j++) {
        if (A[i] == B[j] && $.inArray(A[i],result) == -1) {
            result.push(A[i]);
        }
    }
}
return result;
}