Javascript -帮助更新我的计算器的显示，以显示按下的按钮的数量

// HTML部分
<button id="btn1">按钮1</button>
<button id="btn2">按钮2</button>
<button id="btn3">按钮3</button>
<p id="count">按钮数量：0</p>

// JavaScript部分
var btn1 = document.getElementById("btn1");
var btn2 = document.getElementById("btn2");
var btn3 = document.getElementById("btn3");
var countDisplay = document.getElementById("count");

var count = 0;

btn1.addEventListener("click", function() {
  count++;
  updateCountDisplay();
});

btn2.addEventListener("click", function() {
  count++;
  updateCountDisplay();
});

btn3.addEventListener("click", function() {
  count++;
  updateCountDisplay();
});

function updateCountDisplay() {
  countDisplay.textContent = "按钮数量：" + count;
}