1、数组取差
//es6
arryMinus (arry1,arry2){
let a = new Set(arry1);
let b = new Set(arry2);
let difference = new Set([…a].filter(x => !b.has(x)));
return Array.from(difference);
}
// 循环
arryMinus (arry1,arry2){
var arr3 = new Array();
for(var i=0; i < arry1.length; i++){
var flag = true;
for(var j=0; j < arry2.length; j++){
if(arry1[i] == arry2[j]) {
flag = false;
}
}
if(flag){
arr3.push(arry1[i]);
}
}
return arr3;
}
2、数组取交集
//es6
arryIntersect (arr1,arr2){
// 利用 set 方法取交集
let a = new Set(arr1);
let b = new Set(arr2);
let intersect = new Set([…a].filter(x => b.has(x)));
return Array.from(intersect);
}
arryIntersect (arr1,arr2){
// 循环判断数组 a 里的元素在 b 里面有没有，有的话就放入新建立的数组中
var ai=0, bi=0;
var result = new Array();
while (ai < a.length && bi < b.length)
{
if (a[ai] < b[bi] ) {ai++;}
else if (a[ai] > b[bi] ) {bi++;}
else /* they’re equal */
{
result.push (a[ai] );
ai++;
bi++;
}
}
return result;
}
3、数组去重
//es6
arryUnique (array){
// 去除数组的重复成员
return […new Set(array)]
}
arryUnique (array){
var res = [];
var json = {};
for(var i = 0; i < this.length; i++){
if(!json[this[i]]){
res.push(this[i]);
json[this[i]] = 1;
}
}
return res;
}