callback and arrow.js

var request = require('request');
var url1 = 'http://beta.json-generator.com/api/json/get/414r5rM-z';
var url2 = 'http://beta.json-generator.com/api/json/get/VJqDcHMbM';
/* normal callback */
function getdata1(callback)
{
	request.get(url1,function (error, response, body) {
    	callback((JSON.parse(body)).success);
	});
}
function getdata2(s)
{
	request.get(url2,function (error, response, body) {
    		console.log(s + " " + (JSON.parse(body)).success);
		});
}
getdata1(getdata2);

/* Promise */
function p_get1()
{
	return new Promise(function(resolve, reject){
       request.get(url1,function (error, response, body) {
    		resolve((JSON.parse(body)).success);
		});
    });
}
function p_get2(s)
{
	return new Promise(function(resolve, reject){
       request.get(url2,function (error, response, body) {
    		console.log(s + " " + (JSON.parse(body)).success);
		});
    });
}
p_get1().then(p_get2);

/* arrow */
p_get1().then(s => p_get2(s));

/* Generator */
function* run(){
	var s1 = yield p_get1();
	yield p_get2(s1);
}
var gen = run();
gen.next().value.then(function(r1){
  //第一個Promise結束後，把r1丟回給generator
  gen.next(r1);
  console.log('done');
});

/* async */
//

/* arrow function */
function add(a,b){
	return a+b;
}
console.log(add(1,2));

var c = (a,b) => a+b;
console.log(c(1,2));

var d = (a,b) => {if(a>b){return a;}else{return b;}};

console.log(d(1,2));
console.log(d(3,2));