Wejście z przyciskami plus i minus
<div>
<input id="numberInput"/>
<button id="plusButton">+</button>
<button id="minusButton">-</button>
</div>
<script>
textInput = document.querySelector('#numberInput');
plusButton = document.querySelector('#plusButton');
minusButton = document.querySelector('#minusButton');
plusButton.onclick = () => textInput.value = parseInt(textInput.value) + 1;
minusButton.onclick = () => textInput.value = parseInt(textInput.value) - 1;
</script>
Beautiful Bear