test922a.js

function * serial() {
	var c = 0;
	while(true) {
		yield c;
		c++;
	}
}
var s = serial();
console.log(s.next().value);
//顯示 0
console.log(s.next().value);
//顯示 1
console.log(s.next().value);
//顯示 2