Count animation from number A to B

Question

I am updating a numeric value inside an element by doing intervalled ajax requests.

To make the whole thing a bit more alive,

Answer 1

This is what i came up with:

function animateVal(obj, start=0, end=100, steps=100, duration=500) {   
    start = parseFloat(start)
    end = parseFloat(end)

    let stepsize = (end - start) / steps
    let current = start
    var stepTime = Math.abs(Math.floor(duration / (end - start)));
    let stepspassed = 0
    let stepsneeded = (end - start) / stepsize

    let x = setInterval( () => {
            current += stepsize
            stepspassed++
            obj.innerHTML = Math.round(current * 1000) / 1000 
        if (stepspassed >= stepsneeded) {
            clearInterval(x)
        }
    }, stepTime)
}   

animateVal(document.getElementById("counter"), 0, 200, 300, 200)