Javascript：如何停止计时器并启动计时器

Question

I'm new to Javascript and decided my project for learning and developing further is by making a video game and my current problem is with a timer system.

Here is the situation. Your character has energy which will be used up when you use skills. (Ex: -5 energy loss for X skill). I created a timer for a energy regeneration feature which gives you 1 energy point per second.

Now I have two problems with this system. The first one being that when my timer goes off because you reached your CAP energy, it doesn't start regenerating again, so how can I get the timer to continue once it starts to drain?

My second problem is I learned that when i'm actually using the skills, and 5 energy points is being costed, this does not reset the time. (Ex: 31.. 32.. (use skill -5 energy) 27.. 33.. 34...) So basically it will not register the -5 energy on the timer.

Here is my code.

var count = character.energy;
var counter = setInterval(timer, 1000); 

function timer() { 
  count += characterstats.energyregen;
  if (count >= 35){
     clearInterval(counter);
  }

  document.getElementById("energy").innerHTML = count;
  character.energy = count;
}

Answer 1

Why not just add a check for the timer's state when using a skill? You know for a fact when a skill is used, energy is not at maximum - go ahead and start the timer when a skill is used if it's not already running.

function useSkill(skill) {
    if (!isTimerRunning) {
      timer.Start();
    }
    invokeSkillUseMethodHere();
}

Answer 2

1) Add another condition to your if, ie (if count >= 35 && timerRegen == false) and then at the end of your skills add timerRegen = true or something along those lines -- the specifics are murky because I don't follow your entire logic with only seeing your timer

2) You need to put the time variable outside the scope of the timer function, so that skills alter it.

e-- thank you to the user below for pointing out the errors