如何在点击按钮时增加和减少数值？

<button id="increaseBtn">增加</button>
<button id="decreaseBtn">减少</button>
<span id="value">0</span>

var increaseBtn = document.getElementById("increaseBtn");
var decreaseBtn = document.getElementById("decreaseBtn");
var valueElement = document.getElementById("value");

increaseBtn.addEventListener("click", function() {
  var currentValue = parseInt(valueElement.innerText);
  valueElement.innerText = currentValue + 1;
});

decreaseBtn.addEventListener("click", function() {
  var currentValue = parseInt(valueElement.innerText);
  valueElement.innerText = currentValue - 1;
});

button {
  padding: 10px;
  background-color: #007bff;
  color: #fff;
  border: none;
  cursor: pointer;
}

span {
  font-size: 24px;
  font-weight: bold;
}