(JS) iterator mode

（JS） Iterator pattern
Sequential access to a collection
The consumer does not need to know the internal structure of the collection

class Iterator {
    
	constructor(container) {
    
		this.list = container.list;
		this.index = 0;
	}
	next() {
    
		if(this.hasNext()) {
    
			return this.list[this.index++];
		}
		return null;
	}
	hasNext() {
    
		if(this.index>=this.list.length) {
    
			return false;
		}
		return true;
	}
}
class Container {
    
	constructor(list) {
    
		this.list = list;
	}
	getIterator() {
    
		return new Iterator(this)
	}
}

var arr = [1,2,3,4,5,6,7];
var container = new Container(arr);
var iterator = container.getIterator();
while (iterator.hasNext()) {
    
	console.log(iterator.next())
}