Return value from nested function in Javascript

Question

I have a function that is set up as  follows  function mainFunction           function subFunction                 var str    foo               return str             var test   mainFunction    alert test     To my logic  that alert should return  foo   but instead it returns undefined  What am I doing wrong   UPDATE  Here s my actual code  it s a function for reverse-geocoding with the Google API   function reverseGeocode latitude longitude       var address           var country           var countrycode           var locality            var geocoder   new GClientGeocoder        var latlng   new GLatLng latitude  longitude         return geocoder getLocations latlng  function addresses         address   addresses Placemark 0  address       country   addresses Placemark 0  AddressDetails Country CountryName       countrycode   addresses Placemark 0  AddressDetails Country CountryNameCode       locality   addresses Placemark 0  AddressDetails Country AdministrativeArea SubAdministrativeArea Locality LocalityName       return country

User · Answer

Just FYI  Geocoder is asynchronous so the accepted answer while logical doesn t really work in this instance  I would prefer to have an outside object that acts as your updater      var updater        function geoCodeCity goocoord         var geocoder   new google maps Geocoder        geocoder geocode            latLng   goocoord        function results  status            if  status    google maps GeocoderStatus OK                updater currentLocation   results 1  formatted address            else               if  status     ERROR                          console log status

User · Answer

Right  The function you pass to getLocations   won t get called until the data is available  so returning  country  before it s been set isn t going to help you    The way you need to do this is to have the function that you pass to geocoder getLocations   actually do whatever it is you wanted done with the returned values    Something like this   function reverseGeocode latitude longitude     var geocoder   new GClientGeocoder      var latlng   new GLatLng latitude  longitude      geocoder getLocations latlng  function addresses        var address   addresses Placemark 0  address      var country   addresses Placemark 0  AddressDetails Country CountryName      var countrycode   addresses Placemark 0  AddressDetails Country CountryNameCode      var locality   addresses Placemark 0  AddressDetails Country AdministrativeArea SubAdministrativeArea Locality LocalityName      do something with address address  country  countrycode  locality               function do something with address address  country  countrycode  locality      if  country    USA          alert  USA A-OK        or whatever           If you might want to do something different every time you get the location  then pass the function as an additional parameter to reverseGeocode   function reverseGeocode latitude longitude  callback        Function contents the same as above  then   callback address  country  countrycode  locality     reverseGeocode latitude  longitude  do something with address     If this looks a little messy  then you could take a look at something like the Deferred feature in Dojo  which makes the chaining between functions a little clearer

User · Answer

you have to call a function before it can return anything   function mainFunction           function subFunction                 var str    foo               return str                return subFunction       var test   mainFunction    alert test     Or   function mainFunction           function subFunction                 var str    foo               return str                return subFunction     var test   mainFunction    alert  test        for your actual code  The return should be outside  in the main function  The callback is called somewhere inside the getLocations method and hence its return value is not recieved inside your main function   function reverseGeocode latitude longitude       var address           var country           var countrycode           var locality            var geocoder   new GClientGeocoder        var latlng   new GLatLng latitude  longitude        geocoder getLocations latlng  function addresses         address   addresses Placemark 0  address       country   addresses Placemark 0  AddressDetails Country CountryName       countrycode   addresses Placemark 0  AddressDetails Country CountryNameCode       locality   addresses Placemark 0  AddressDetails Country AdministrativeArea SubAdministrativeArea Locality LocalityName                 return country

[javascript] Return value from nested function in Javascript

Examples related to javascript

Examples related to function

Examples related to nested

Examples related to return-value

Examples related to return