1//Symbol数据类型 描述
let symbol1 = Symbol(1);
console.log(symbol1);
//Symbol应用 私有属性
function Perent() {
let a = Symbol();
this[a] = '王';
this.getA = () => {
return this[a];
}
}
let p = new Perent();
console.log(p.fangfa());
2// 集合结构 Set 引用数据类型 内数据具有唯一性
let set1 = new Set();
console.log(set1);
(1) //Set 方法
set1.add(10).add(20).add(30).delete(10);
console.log(set1, set1.size);
let set2 = set1;
set2.clear();
console.log(set1, set2);
(2)//forEach
let set3 = new Set();
set3.add(10).add(20).add(40);
set3.forEach((v, k) => {
console.log(v, k);//v==k 留一个就行
})
3 //数组去重
//01 法
let shuZhu = [10, 10, 10, 40, 90, 90, 90, 100];
let shuZhu1 = [];
for (let i = 0; i < shuZhu.length; i++) {
if (shuZhu1.indexOf(shuZhu[i]) == -1) {
shuZhu1[shuZhu1.length] = shuZhu[i];
}
}
console.log(shuZhu1);
//02 法
let shuZhu = [10, 10, 10, 40, 90, 90, 90, 100];
for (let i = 0; i < shuZhu.length; i++) {
for (let j = i + 1; j < shuZhu.length; j++) {
if (shuZhu[i] == shuZhu[j]) {
shuZhu.splice(j, 1);
j--;
}
}
}
console.log(shuZhu);
//03 法 Set内数据具有唯一性
let shuZhu = [10, 10, 10, 40, 90, 90, 90, 100];
let set = new Set(shuZhu);
console.log(Array.from(set));
//04 法
let diandian = [...new Set(shuZhu)];
console.log(diandian);
