当属性值等于css类名时追加文本

<button class="btn" data-status="active">点击我</button>

.btn {
  padding: 10px 20px;
  font-size: 16px;
}

.active {
  background-color: green;
  color: white;
}

document.addEventListener('DOMContentLoaded', function() {
  const buttons = document.querySelectorAll('.btn');
  buttons.forEach(button => {
    if (button.getAttribute('data-status') === 'active') {
      button.textContent += ' 已激活';
    }
  });
});

document.addEventListener('DOMContentLoaded', function() {
  const buttons = document.querySelectorAll('.btn');
  buttons.forEach(button => {
    if (button.getAttribute('data-status') === 'active') {
      button.textContent += ' 已激活';
    }
  });
});