1、Promise.all 全部執行完回撥var p1 = new Promise(function (resolve, reject) {
    setTimeout(resolve, 500, 'P1');
});
var p2 = new Promise(function (resolve, reject) {
    setTimeout(resolve, 600, 'P2');
});
// 同時執行p1和p2，並在它們都完成後執行then:
Promise.all([p1, p2]).then(function (results) {
    console.log(results); // 獲得一個Array: ['P1', 'P2']
 

});

2、Promise.race 返回最快的那個結果，另一個結果被拋棄var p1 = new Promise(function (resolve, reject) {
    setTimeout(resolve, 500, 'P1');
});
var p2 = new Promise(function (resolve, reject) {
    setTimeout(resolve, 600, 'P2');
});
Promise.race([p1, p2]).then(function (result) {
    console.log(result); // 'P1'
});3、按順序執行
 
var p = new Promise(function (resolve, reject) {
    log('start new Promise...');
    resolve(123);
});


p.then(p1)
 .then(p1)
 .then(p3)
 .then(p4)
 .then(function (result) {
    log('Got value: ' + result);
});  
詳細原文地址：https://www.liaoxuefeng.com/wiki/001434446689867b27157e896e74d51a89c25cc8b43bdb3000/0014345008539155e93fc16046d4bb7854943814c4f9dc2000