更改关闭的div按钮的文本

<button id="closeBtn">关闭</button>

var closeBtn = document.getElementById("closeBtn");
closeBtn.addEventListener("click", function() {
    // 在这里编写关闭div的代码
});

var divElement = document.getElementById("divId");
divElement.style.display = "none";

closeBtn.innerHTML = "展开";

<button id="closeBtn">关闭</button>
<div id="divId">要隐藏的div内容</div>

<script>
var closeBtn = document.getElementById("closeBtn");
var divElement = document.getElementById("divId");

closeBtn.addEventListener("click", function() {
    if (divElement.style.display === "none") {
        divElement.style.display = "block";
        closeBtn.innerHTML = "关闭";
    } else {
        divElement.style.display = "none";
        closeBtn.innerHTML = "展开";
    }
});
</script>