[ES6] 17. Set

Es6 provides "Set", it likes array but the data inside should be unqiue.

"Set" is a construct function, you should call:

var s = new Set();

Methods:

---

1. add(value)

[2,3,5,4,5,2,2].map(x =>s.add(x) )
for(num of s){
 console.log(num);   
}

//2, 3, 5, 4

2. delete(value)

[2,3,5,4,5,2,2].map(x =>s.add(x) );

s.delete("3");

for(num of s){
 console.log(num);   
}

//2, 5, 4

3. has(value)

[2,3,5,4,5,2,2].map(x =>s.add(x) );

s.delete("3");

for(num of s){
 console.log(num);   
}

s.has("3"); //false

4. size()

[2,3,5,4,5,2,2].map(x =>s.add(x) )
for(num of s){
 console.log(num);   
}

s.size(); // 4

5. claer()

[2,3,5,4,5,2,2].map(x =>s.add(x) )
for(num of s){
 console.log(num);   
}

s.clear(); 
s.size(); // 0