JavaScript中的回调函数

Question

I have two functions , Function submitCallbackInfo is callback function in a loop and XYZ . I only want to execute XYZ once i receive all data from submitCallbackInfo without using timeout or jQuery.

for (var i = 0; i < 10; i++) {
  var id;
  myHttp1.connect(url, 'GET', data, submitCallbackInfo);
}

setTimeout(XYZ, 5000);

What i exactly want is to call XYZ function only when submitCallbackInfo executes 10 times.

Answer 1

Check the value of counter in the callback function

var length = 10;
var count = 0;

function submitCallbackInfo() {
  if (++count === length) {
    createC2VCall();
  }
}

for (var i = 0; i < length; i++) {
  myHttp1.connect(url, 'GET', data, submitCallbackInfo);
}

Promise could be used if myHttp1.connect returns a Promise-object

Answer 2

Alternate to @ Rayon 's answer, you can pass count as parameter. You can use .bind() to do it.

Following is a basic implementation

 for (var i = 0; i < 10;) { //myHttp1.connect(url, 'GET', data, submitCallbackInfo.bind(++i)); test(submitCallbackInfo.bind(null, ++i)) } function submitCallbackInfo(count){ var maxCount = 10; console.log('Inside Callback', count) // Do your stuff if(count === maxCount) XYZ(); } function XYZ(){ console.log('Inside XYZ') } function test(callback){ if(callback) callback(); }