Javascript / jQuery make函数在继续之前等待回调

Question

I need to know how to make a function wait for a callback from another function before executing. Below is a simplified scenario of what I am trying to accomplish.

function a(){
  b();
  // Wait for function c to callback
  var callback = function();
  // then continue function a() logic...
}
function b(){
  c();
  return false;
}

function c(){
  //trigger callback in function a
    callback();
}

Answer 1

Put the rest of a's logic into the callback, and if you need, use a reference to a's this

function a(){
  b();
  var that = this;
  var callback = function(){
    that.variables
    // then continue function a() logic...
  }
}
function b(){
  c();
  return false;
}

function c(){
  //trigger callback in function a
    callback();
}

Answer 2

What you need to do is to pass a callback to b and c as shown below and call the callback in c after its execution... assuming c is doing an async operation.

 function a() { snippet.log('inside a'); b(function() { //code that should be executed after `c` must be here... note that you cannot return a value from here to the caller of `a` snippet.log('inside callback'); }); snippet.log('after b') } function b(callback) { snippet.log('inside b'); c(callback); return false; } function c(callback) { snippet.log('inside c'); setTimeout(function() { snippet.log('inside async timeout'); //trigger callback in function a callback(); }, 100); } a(); 

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