打破Javascript的每个功能

Question

Please don't mark duplicate or give negative mark before reading it carefully.

Break from .each function of Mongodb cursor function after reading all documents & continue for logic further. I know there is no break statement for each loop.

I am looping over each document in Mongodb & after finishing off i want to do my further logic. If i give 'return' statement it will take me out of function. i don't want to go out of function.

function update (){               
          var resultCursor = dbCollection.find();
           resultCursor.each(function(err, result) {
           if (result == null)
           {
            //// I want to break from here & continue to logic further
             //return false;

           };
           console.log('result  for each item is ',result);

           //Calculate distance for from location if < 1000 meters
            riderFromLat = reqBody.fromLoc.lat;
            riderFromLong = reqBody.fromLoc.lng;

          var fromDistance = geolib.getDistance({latitude: riderFromLat, longitude: riderFromLong }, {latitude: result.fromLoc.coordinates[0], longitude: result.fromLoc.coordinates[1]});

         console.log(' From Distance is ',fromDistance);
          if ( fromDistance < 1000 )
            {

          riderToLat = reqBody.toLoc.lat;
          riderToLong = reqBody.toLoc.lng;

             var toDistance = geolib.getDistance({latitude: riderToLat, longitude: riderToLong }, {latitude: result.toLoc.coordinates[0], longitude: result.toLoc.coordinates[1]});
              console.log(' To Distance is ',toDistance);

               if (toDistance <= 1000)
                {
                   jsonResultData.finalMatchDriverList.push(result);
                }
            }
         });


        // Want to continue with logic further here over jsonResultData
 console.log ('jsonResultData.finalMatchDriverList.length',jsonResultData.finalMatchDriverList.length );
} 

Question :- I want to loop over each document & after looping i want to continue my code further. Hopefully there must be solution for this one. Need some guidance for that only.

Answer 1

I'm not familiar with MongoDB and can't judge if there's a better way of doing it (and probably there is) but given your description this is possibly what you want:

function update (){
      var results = [];

      function  doThisAfterwards() {
        // you can access results here; 
      }

      var resultCursor = dbCollection.find();
       resultCursor.each(function(err, result) {
           if(result) {
                // do what you want
                results.push(result);
           }
           else  {
                doThisAfterwards();
           }
       );
}