index.html

// Making stopwatch

  <section>
    <p1>0m</p1>
    <p2>0s</p2>
    
    <button id="start">Start</button>
    <button id="reset">Reset</button>
    
  </section>
  
  <script> 
    
    let start = document.querySelector("#start")
    let stop = document.querySelector("#stop")
    let restart = document.querySelector("#restart")
    let p1 = document.querySelector("p1")  
    let p2 = document.querySelector("p2") 
    
    let seconds = 0;
    let minutes = 0;
    let timer;
    
    function startTimer(){
    timer = setInterval(updateDisplay, 1000)
    updateDisplay()
    };     
    
    function updateDisplay(){
        if (seconds == 59){
          minutes = minutes + 1;
          seconds = -1;
        }
      
      seconds++;
      p1.innerHTML = `${minutes}m`
      p2.innerHTML = `${seconds}s`
      console.log("interval running", seconds)  
    }
    
    function stopTimer(){
      clearInterval(timer)
    }
    
    function resetTimer(){
      stopTimer()
      console.log("reset")
      seconds = -1;
      minutes = 0;
      updateDisplay()
    }
       
    start.addEventListener('click', startTimer)
    reset.addEventListener('click', resetTimer)
    
    
  </script>