Angularjs - using Typeahead should show 2 values

I use typeahead

, I like to get dynamic data, more useful

 <input required type="text" ng-model="student" 
  placeholder="{{'STUDENT_ID_FIRST_NAME_LAST_NAME' | translate}}" 
  typeahead="student as student.lastName for student in getStudents($viewValue)"
  typeahead-loading="loading" class="form-control">

      

        
        
        
      

    

My javascript code for fetching students is -

$scope.getStudents = function(val) {
    var queryCriteria = {
        q: JSON.stringify([{
            field: 'lastName',
            op: APP_CONSTANTS.SEARCH_OPERATORS.CONTAINS,
            value: val
        }, {
            field: 'firstName',
            op: APP_CONSTANTS.SEARCH_OPERATORS.CONTAINS,
            value: val
        }, {
            field: 'userId',
            op: APP_CONSTANTS.SEARCH_OPERATORS.CONTAINS,
            value: val
        }]),
        joinCondition: APP_CONSTANTS.JOIN_CONDITIONS.OR,
        order: APP_CONSTANTS.SORTING_ORDER.DESCENDING,
        limit: 10,
        orderBy: 'createdAt',
        page: 1
    }
    return Students.query(queryCriteria).then(function(response) {
        return response.data;
    });
};

      

        
        
        
      

    

I want to show the concatenation of student.lastName

and student.firstName

. Please suggest how to do this.