promise 个人练习

一些题目

Promise.resolve()
            .then(() => {
                console.log(0)
                return Promise.resolve().then(() => {
                    // return 回去 8
                    console.log(2)
                    return Promise.resolve().then(() => {
                        // return 回去 6
                        console.log(4)
                    })
                })
            })
            .then(() => console.log('完事了', 10))

        Promise.resolve()
            .then(() => {
                console.log(1)
            })
            .then(() => {
                console.log(3)
            })
            .then(() => {
                console.log(5)
            })
            .then(() => {
                console.log(7)
            })
            .then(() => {
                console.log(9)
            })
            .then(() => {
                console.log(11)
            })
            .then(() => {
                console.log(12)
            })