updating embedded array in MongoDB -

i trying update embedded array document in collection structure

        {             id: 1,             fields:[                  {                     "lang" : "eng","embeddedarray" : ["a","b","c"]                 },                 {                    "lang" : "abcd","embeddedarray" :["a","d","e"]                 }]         } 

i want update in embeddedarray try update using query updating entire array 'a' instead of ['a','b','c']

db.collectionname.update({"fields.embeddedarray" : 'a'}, {"$set" : {"fields.$.embeddedarray" : "a"}}); 

is way update without loosing other elements in array ?

please check below query :

db.collectionname.find({"fields":{$elemmatch:                        {"lang":"a"}}}).foreach(function(doc){                          var fields = doc.fields;                          var i,k;                         for( i=0; i<fields.length; i++ )                           {                        k = fields[i].embeddedarray.indexof("a");                        fields[i].embeddedarray.splice(k,1,"a");                           }  db.collectionname.update({ _id: doc._id},{$set:{"fields": fields}}); });