Ответ:
- Абстрактный метод – метод без реализации, который должен быть переопределен в наследнике.
- Интерфейс – чистая абстракция (до Java 8), содержит только абстрактные методы (начиная с Java 8, допускает default и static методы).
tags: #собеседование
BY JavaRocks
Secure video calling is in high demand. As an alternative to Zoom, many people are using end-to-end encrypted apps such as WhatsApp, FaceTime or Signal to speak to friends and family face-to-face since coronavirus lockdowns started to take place across the world. There’s another option—secure communications app Telegram just added video calling to its feature set, available on both iOS and Android. The new feature is also super secure—like Signal and WhatsApp and unlike Zoom (yet), video calls will be end-to-end encrypted.
Launched in 2013, Telegram allows users to broadcast messages to a following via “channels”, or create public and private groups that are simple for others to access. Users can also send and receive large data files, including text and zip files, directly via the app.The platform said it has more than 500m active users, and topped 1bn downloads in August, according to data from SensorTower.JavaRocks from ua