js改变按钮属性值

document.getElementById("myButton").innerHTML = "新的按钮文本";

document.getElementById("myButton").style.backgroundColor = "blue";
document.getElementById("myButton").style.color = "white";

// 禁用按钮
document.getElementById("myButton").disabled = true;

// 启用按钮
document.getElementById("myButton").disabled = false;

// 添加一个类
document.getElementById("myButton").classList.add("newClass");

// 移除一个类
document.getElementById("myButton").classList.remove("oldClass");

// 切换一个类
document.getElementById("myButton").classList.toggle("toggleClass");

<button id="myButton" class="btn">点击我</button>

// 获取按钮元素
var button = document.getElementById("myButton");

// 改变按钮文本
button.innerHTML = "已点击";

// 改变按钮样式
button.style.backgroundColor = "green";
button.style.color = "white";

// 禁用按钮
button.disabled = true;

document.addEventListener("DOMContentLoaded", function() {
    var button = document.getElementById("myButton");
    button.innerHTML = "已点击";
    button.style.backgroundColor = "green";
    button.style.color = "white";
    button.disabled = true;
});