点我去中部

<button>点击我去到页面中间</button>

btn=document.querySelector("button"),

var scrollTop=document.documentElement.scrollTop || window.pageYOffset || document.documentElement.scrollTop
console.log(scrollTop);
btn.addEventListener("click",function(){
document.body.scrollTop=200;
window.pageYOffset=200;
document.documentElement.scrollTop=200;
})