Returning json array from a function to a variable-Collection of common programming errors

• Try like this:

  function map_address(addr, callback) {
  
      var input_address = addr;
      var geocoder = new google.maps.Geocoder();
      geocoder.geocode( { address: input_address }, function(results, status) {
          if (status == google.maps.GeocoderStatus.OK) {
              var lat = results[0].geometry.location.lat();
              var lng = results[0].geometry.location.lng();
  
  
                                 jsonarr={'lat':lat,'lng':lng}
                                 alert(jsonarr.lat);
                                 callback(jsonarr) ;
  
  
                              }
          else {
              alert("Nessuna coordinata trovata da questo indirizzo!");
              }
          });
  }
  map_address("hogehoge", function(result){
    alert(result)
  });
  

• the geocoder.geocode(..); function is asynchronous as it wraps another function inside that will be called later when the geocode operation is done.

  because of this map_address(...) will always return undefined

• Thanks all for the answers, i put all my code inside the callback and all work fine this is the final code.

     function map_address(addr,callback)
          {
  
              var input_address = addr;
              var geocoder = new google.maps.Geocoder();
              geocoder.geocode( { address: input_address }, function(results, status) {
                  if (status == google.maps.GeocoderStatus.OK) 
                  {
                      var lat = results[0].geometry.location.lat();
                      var lng = results[0].geometry.location.lng();
  
                      jsonarr={'lat':lat,'lng':lng}                       
                      return callback(jsonarr);                        
                  }
                  else {
                      alert("No coord find");
                  }
              });
          }
  
  
  $(document).ready(function(){ 
     $(window).load(function(){ 
  
  map_address('address string',function(coord){
  
  
    var center=new google.maps.LatLng(coord.lat,coord.lng);
  
  
  
    var settings = {
            zoom: 16,
            center: center,
            mapTypeControl: false,
            mapTypeControlOptions: {style: google.maps.MapTypeControlStyle.DROPDOWN_MENU},
            navigationControl: true,
            navigationControlOptions: {style: google.maps.NavigationControlStyle.SMALL},
            mapTypeId: google.maps.MapTypeId.ROADMAP
        }; 
  
    var map=new google.maps.Map(document.getElementById("map"), settings);
  
  var marker = new google.maps.Marker({
  position: new google.maps.LatLng(coord.lat,coord.lng),
  map: map
  });
  
  
  });
  });
  
  });
  

Originally posted 2013-11-09 23:09:52.