Countdown exercise

Make a kitchen timer. Modify the countdown() function in countdown.js to take a number of seconds, then print each second counting down to zero.

countdown(10);

// should print

// 10...
// 9...
// 8...
// ...

Levels

1. Use global variable to keep track of time
2. Keep track of time without defining any global variables
3. BONUS: don't define any new variables

Documentation

• setTimeout()
• setInterval()
• clearInterval()