Multiple choice

Which of the following codes will record the current system time and send a message to the handler starting the timer and remove any existing message before sending the next one?

  1. Private void startTimer(){
   mSt=System.currentTimeMillis();
   mHandler.removeMessages(0);
   mHandler.sendEmptyMessage(0);
}

  2. Private void startTimer(){
   mSt=System.currentTime();
   mHandler.removeMessages(0);
   mHandler.sendEmptyMessage(0);
}

  3. Private void startTimer(){
   mSt=System.currentTimeMillis();
   mHandler.removeMessage(0);
   mHandler.sendEmptyMessage(0);
}

  4. Private void startTimer(){
   mSt=System.currentTimeMillis();
   mHandler.removeMessages(0);
   mHandler.sendEmptyMessages(0);
}
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A Correct answer
Explanation

The code for recording the current system time and sending a message to the handler, starting the timer and removing any existing messages before sending the next one is as follows:

Private void startTimer() {
 mSt = System.currentTimeMillis();
 mHandler.removeMessages(0);
 mHandler.sendEmptyMessage(0);
}

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