Auto increment animated counter example

index.js

// auto increment counter
// select elements
      var yearOfExperiences = document.getElementById("yearOfExperiences")
      var dedicatedEmployees = document.getElementById("dedicatedEmployees")
      var serviceProvides = document.getElementById("serviceProvides")
      var largeScaleGovmentProject = document.getElementById("largeScaleGovmentProject"
     )

      function animate(obj, initVal, lastVal, duration) {
        let startTime = null

        //get the current timestamp and assign it to the currentTime variable
        let currentTime = Date.now()

        //pass the current timestamp to the step function
        const step = (currentTime) => {
          //if the start time is null, assign the current time to startTime
          if (!startTime) {
            startTime = currentTime
          }

          //calculate the value to be used in calculating the number to be displayed
          const progress = Math.min((currentTime - startTime) / duration, 1)

          //calculate what to be displayed using the value gotten above
          obj.innerHTML =
            Math.floor(progress * (lastVal - initVal) + initVal) + "+"

          //checking to make sure the counter does not exceed the last value (lastVal)
          if (progress < 1) {
            window.requestAnimationFrame(step)
          } else {
            window.cancelAnimationFrame(window.requestAnimationFrame(step))
          }
        }

        //start animating
        window.requestAnimationFrame(step)
      }

      const load = () => {
        animate(yearOfExperiences, 0, 16, 800)
        animate(dedicatedEmployees, 0, 1000, 800)
        animate(serviceProvides, 0, 300, 800)
        animate(largeScaleGovmentProject, 0, 200, 800)
      }