[gist]Why Promises will make async easy

EasonTyler 發(fā)布于2019-08-21 10:17 / 2757人閱讀

摘要：有許多理由你將會(huì)需要用到好吧先來解釋一下什么是。這類似于我們經(jīng)常使用的返回的那個(gè)玩意比如想要在對(duì)請(qǐng)求來的數(shù)據(jù)做加工

from http://oyanglul.us

What is Promises

Promise is a proxy for a value not knowing when its creation time. It provide 2 Methods then and catch, which return promise so they can be chained.

Promise.prototype.then(onFulfilled, onRejected)

Appends fullfillment and rejection handlers to the promise, and returns a new promise resolving to the return value of the called handler.

Promise.prototype.catch(onRejected)

Appends a rejection handler callback to the promise, and returns a new promise resolving to the return value of the callback if it is called, or to its original fulfillment value if the promise is instead fulfilled.

Why Promises

there are so many reasons you should use promise in you client rich project if you are not using any MV* frameworks.

有許多理由你將會(huì)需要用到 Promises. 好吧先來解釋一下什么是 Promises 。這類似于我們經(jīng)常使用的 jQuery.ajax() 返回的那個(gè)玩意 – Deferreds.

比如想要在對(duì) ajax 請(qǐng)求來的數(shù)據(jù)做加工

? $.ajax("yourdata.url").then(function(data){
????? // do something with your data
? })

云服務(wù)器 GPU云服務(wù)器 gist Will why Promises

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