remove $$hashKey from array

Based on your comment that you need to insert the array into the database, I'm going to assume that you are converting it a JSON string and then saving it to the DB. If that's incorrect, let me know and I'll see if I can revise this answer.

You have two options for modifying your array when converting it to JSON. The first is angular.toJson, which is a convenience method that automatically strips out any property names with a leading $$ prior to serializing the array (or object). You would use it like this:

var json = angular.toJson( $scope.appdata );

The other option, which you should use if you need more fine grained control, is the replacer argument to the built-in JSON.stringify function. The replacer function allows you to filter or alter properties before they get serialized to JSON. You'd use it like this to strip $$hashKey:

var json = JSON.stringify( $scope.appdata, function( key, value ) {
    if( key === "$$hashKey" ) {
        return undefined;
    }

    return value;
});

Fast solution for lazy people :

JSON.parse(angular.toJson($scope.appdata))