How to synchronously call multiple functions angularjs -

for example, have 4 functions:

var f1 = function() {...}; var f2 = function() {...}; var f3 = function() {...}; var f4 = function() {...}; var fmain = function() {...}; 

the main function loop:

  var fmain = function () {     angular.foreach(question_list, function (question, key) {        f3();  //i want execute f4() after f3() returned!        f4();      });    }; 

in f3(), f2() called!

var f2() = function(){ //there's timeout function check if dynamic value equals expected value //if so, return true; otherwise, keep calling f2() until dynamic value equals expected value } 

in f2(), f1() called!

var f1() = function(){ //there's timeout function check if dynamic value equals expected value //if so, return true; otherwise, keep calling f1() until dynamic value equals expected value } 

so, f3 depends on f2, f2 depends on f1.

i want have them return synchronously (need code not proceed next line if previous line not returned yet). how can implement this?

thanks in advance!

you can use $q service:

var f1() = function(){     var defer = $q.defer();     $timeout(function(){         defer.resolve(f1result);     });     return defer.promise; }  var f2() = function(){    var defer = $q.defer();    f1().then(function(f1result){          defer.resolve(f2result);    });    return defer.promise; } 

f3 function work f1 , f2 (defer,promise , resolve).

var fmain = function () { angular.foreach(question_list, function (question, key) {   f3().then(function(f3result){       f4();   }); }); };