the code is a multi-layer callback. The example code is as follows var arr=[]; let A = ()=>{ B(function(){ C(function(){ let a = 10; arr.push(a); ...
is an example of writing n parameters and n heap execution statements that you don t want to take from other people s articles. I have written three simple examples myself, which contain my understanding and questions about callback functions. I read...
recently learned ES6 , learned promise , you can use then (). Then (). Then () to solve callback hell I would like to ask: like the following simple logic case, the two effects may be the same. so what are the advantages of promise ? if there...
Recently, I have been studying the callback function, which is said to be one of the necessary skills to become a senior programmer. I searched the Internet for most of the day, but until now I haven t figured out the real scene of the callback, so I se...
I wrote all the js about the smart contract in a js, and then called it with the js of the page. The callback function does not return a value. Public js written by oneself index.js localhost ...
Why is the value of this tag 1 and this tag 2 different when the second callback is made by the two calls ? function a (val, callback) { callback.call(a,val,callback) } a(1,function b (val ,callback) { console.log(this, 1 ) ...
encountered a problem with angular development. The framework tinyUi used by provides a spinner component that needs to be initialized with a set of parameters. Html may look like this <cti-spinner ng-repeat="item in list" id="option...
WeChat Mini Programs s wx.request is an asynchronous request. Perform background interaction in app.js onLaunch to obtain openid APP({ onLaunch:function(){ wx.login({ success:res => { var code = re...
when the callback function triggered by the fb sharing event succeeds or fails, the parameters passed are all the same. It is impossible to determine whether the sharing has been successful or failed. Please ask Technical Bull to give us some advice on t...
I am a novice. I encountered some doubts when learning the asynchronism of javascript , as follows: there is an example code like this in teacher Ruan Yifeng s tutorial: does not particularly understand the operation mechanism of the whole mult...
I am a novice. I encountered a little confusion when learning javascript timer. It may be a clich problem, but I still want to ask the elders. The problem and code are as follows: var Cat = function() { var o = { say: function() { ...
for example Promis.all([p1,p2]).then((p1result,p2result)=>{}); if p1 returns [1mem2p3] p2 returns [4mage5magin6] the final result is a parameter [1mem2magin3], what should I do if I want to use the results of two p objects respectively? ...
recently, we need to use the function of real-time comment messages in the project. We use the third-party sdk Fuyun, but I don t know how to initialize and monitor and receive messages in Mini Program. Have you ever used this sdk? ask the god how to us...
The method add (capture-sharp2-of? Super Integer) in the type List < capture-sharp2-of? Super Integer > is not applicable for the arguments (Number) public static void down(List<? super Integer> numberList) { Number x = 4; num...
golang debugging shows very little information, so how to debug? For example, the following compilation error is reported: [root@vagrant-dev web]-sharp go run main.go panic: invalid sql type (slice) for mysql goroutine 1 [running]: github.com jinzhu ...
data batch check and insert, because each record needs to be compared with the data already existing in the database, compare the insertion of OK, compare the generated error messages of non-OK, and export an excel file after all execution. in the pas...
function partial (fn, str1, str2) {} var sayIt = " " partial (sayIt, Hello , Ellie ) ( ! ); ^ ...