前言

总结了一下有关于数组的差集、交集、并集的方法；

es6的方法实现

去重

/**

* 简单的数组去重

* @param {Array} a

*/

const uniquelize = function(a) {

if (a.constructor !== Array) {

throw TypeError("请传入数组类型");

}

return Array.from(new Set(a));

};

并集

/**

* 简单数组的并集

* @param {Array} a

* @param {Array} b

*/

const getUnion = function(a,b){

if(a.constructor === Array && b.constructor === Array){

let set1 = new Set(a);

let set2 = new Set(b);

return Array.from(new Set([...set1,...set2]));

}

return null;

}

交集

/**

* 简单数组的交集

* @param {Array} a

* @param {Array} b

*/

const getIntersect = function(a,b){

if(a.constructor === Array && b.constructor === Array){

let set1 = new Set(a);

let set2 = new Set(b);

return Array.from(new Set([...set1].filter( x => set2.has(x))));

}

return null;

}

差集

/**

* 简单数组的差集

* @param {Array} a

* @param {Array} b

*/

const getDifference = function(a,b){

if(a.constructor === Array && b.constructor === Array){

let set1 = new Set(a);

let set2 = new Set(b);

return Array.from(new Set([...set1].filter(x => !set2.has(x))));

}

return null;

}

es5的方法实现

去重

/**

* 简单的数组去重

* @param {Array} a

*/

var uniquelize = function(a) {

if (a.constructor !== Array) {

throw TypeError("请传入数组类型");

}

var obj = {},

arr = [];

for (var i = 0, j = a.length; i < j; i++) {

if (!obj[a[i]]) {

obj[a[i]] = 1;

arr.push(a[i]);

}

}

return arr;

};

交集

/**

* 简单数组的交集

*/

var getIntersect = function(){

var arr = new Array();

var obj = new Object();

var arguLen = arguments.length;

for(var i = 0; i

if(arguments[i].constructor !== Array){

throw TypeError("请都传入数组类型");

}

for(var j = 0,length = arguments[i].length;j

var item = arguments[i][j];

if(!obj[item]){

obj[item] = 1;

}else{

obj[item]++;

if(obj[item]===arguLen){

arr.push(item);

}

}

}

}

return arr;

}

并集

/**

* 简单数组的并集

*/

var getUnion = function(){

var arr = new Array();

var obj = new Object();

var arguLen = arguments.length;

for(var i = 0; i

if(arguments[i].constructor !== Array){

throw TypeError("请都传入数组类型");

}

for(var j = 0,length = arguments[i].length;j

var item = arguments[i][j];

if(!obj[item]){

obj[item] = 1;

arr.push(item);

}else{

//统计一下出现了多少次

obj[item]++;

}

}

}

return arr;

}

差集

/**

* 简单数组的差集

*/

var getDifference = function(){

var arr = new Array();

var obj = new Object();

var arguLen = arguments.length;

for(var i = 0; i

if(arguments[i].constructor !== Array){

throw TypeError("请都传入数组类型");

}

for(var j = 0,length = arguments[i].length;j

var item = arguments[i][j];

if(!obj[item]){

obj[item] = 1;

arr.push(item);

}else{

obj[item]++;

var index = arr.indexOf(item);

//存在就删除掉

if(index !== -1){

arr.splice(index,1);

}

}

}

}

return arr;

}