ms314006

let str = 'init'

const func = () => {
    str='changed'
}

setTimeout(func,3000)

console.log(str) // ''

ms314006

let data = {}

//使用 async 將 ajax 請求改為同步。
$.ajax({
    url: '',
    async: false,
    success: (status)=>{    
        data = status
    }
)}

ms314006

const newPromise = new Promise((resolve, reject)=>{
    /**成功時回傳**/
    resolve(status)
    
    /**失敗時回傳**/
    reject(status)
}).then((data)=>{
    /**以 then 接續成功時的處理**/
}).catch((error)=>{
    /**以 catch 接續失敗時的處理**/

ms314006

const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('changed')}, 3000)
}).then((data)=>{
    console.log(data) //3 秒後執行，並印出'changed'
})

ms314006

const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{
        if(Math.random() > 0.5){
            resolve('changed')
        }
        else{
            reject('error')
        }
    }, 3000)
}).then((data)=>{

ms314006

const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('changed')}, 3000)
}).then((data)=>{
    console.log(data)  // 'changed'
    return 'last changed'  
}).then((data)=>{
    console.log(data)  // 'last changed'
})

ms314006

const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('changed')}, 3000)
}).then((data)=>{
    console.log(data)
    setTimeout(()=>{data = 'last changed'},2000)
    return data
}).then((data)=>{
    console.log(data) // 'changed'
})

ms314006

const lastPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('last changed')},2000)
})
const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('changed')}, 3000)
}).then((data)=>{
    console.log(data)
    return lastPromise.then((lastData)=>{return lastData})
}).then((data)=>{
    console.log(data) // 'last changed'

ms314006

const newPromise = new Promise((resolve, reject)=>{
    setTimeout(()=>{resolve('changed')}, 3000)
}).then((data)=>{
    console.log(data)
    //第二個Promise
    return new Promise((resolve, reject)=>{
        setTimeout(()=>{resolve('last ' + data)},2000)
    }).then((lastData)=>{
        return lastData
    })

ms314006

const initState = {
    name: 'Jack',
}