js classname赋值

// 获取元素
const element = document.getElementById('myElement');

// 设置className为一个类名
element.className = 'active';

// 设置className为多个类名
element.className = 'active visible';

const element = document.getElementById('myElement');
const classes = ['active', 'visible'];
element.className = classes.join(' ');

const element = document.getElementById('myElement');

function updateClassName(condition) {
  return condition ? 'active' : 'inactive';
}

element.className = updateClassName(true); // 设置为'active'

const element = document.getElementById('myElement');

// 添加类名
element.classList.add('active');

// 移除类名
element.classList.remove('active');

// 切换类名
element.classList.toggle('active');

const element = document.getElementById('myElement');

if (element.classList.contains('active')) {
  console.log('元素包含active类名');
}

const element = document.getElementById('myElement');

// 将'oldClass'替换为'newClass'
element.classList.replace('oldClass', 'newClass');