其中.btns代表在总体的div中定义的class类data-id为在button中定义的标记字符

 

<div class="btns">
        <div class="btn-switch active-map" data-id="0">1</div>
        <div class="btn-switch" data-id="1">2</div>
        <div class="btn-switch" data-id="2">3</div>
  </div>
 
document.querySelector(".btns").addEventListener("click", function(event) {
var id = event.target.getAttribute("data-id");
}