Java Program to create count-down timer.
Objective
Write a Java program to create a single-digit console count-down timer using backspace.
Algorithm / Approach
- Create a loop starting at 9 and going down to 0.
- Inside the loop, print
\b(Backspace) followed by the current number. - Call
Thread.sleep(1000)to pause for 1 second. - Once the loop ends, print the final message.
CountDown.java
class CountDown {
public static void main(String [] ar)
throws Exception {
int i = 9;
while(i!=0){
System.out.print("\b"+i);
i--;
Thread.sleep(1000);
}
System.out.println("\b****************");
System.out.println(" HAPPY BIRTHDAY ");
System.out.println("****************");
}
}Expected Output
//after count-down //from 9 to 0 **************** HAPPY BIRTHDAY ****************
Explanation of the Program
- The
\bcharacter is an escape sequence for Backspace. It moves the terminal cursor back one space. - By printing a backspace and immediately printing the next number, we overwrite the previous number on the exact same spot in the terminal, creating the illusion of a digital countdown timer.
Complexity
Time Complexity
O(1)
Space Complexity
O(1)
