<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div style="display: flex;">
<button style="width: 50px;height: 50px;" id="arttir">+</button>
<h1 id="deger" style="margin-top: 10px;">0</h1>
<button style="width: 50px;height: 50px;" id="azalt">-</button>
</div>
<div style="display: flex;">
<span id="altdeger">0</span>
</div>
<script>
let arttir = document.getElementById("arttir")
let azalt = document.getElementById("azalt")
let deger = document.getElementById("deger")
let altdeger = document.getElementById("altdeger")
let value = 0
arttir.addEventListener("click",e => {
value++
deger.innerHTML = value.
altdeger.innerHTML = value.
e.preventDefault();
})
azalt.addEventListener("click",e => {
value--
deger.innerHTML = value.
altdeger.innerHTML = value.
e.preventDefault();
})
</script>
</body>
</html>