javascript - Javascript：使用 for 循环函数更改 css

Question

每次单击按钮时，我都想增加球元素的 margin-top px 值。我的代码有什么问题？

let ballMargin = ball.style.marginTop;

moveButton.addEventListener('click', function moveDown() {
    for (let i = 0; i < ballMargin.length; i++) {
        ballMargin[i] += '10px';
    }
});

标签： javascript

Answer 1

我举一个简单的例子。我希望它对你有用

let moveButton = document.getElementById("moveButton");
let ball = document.getElementById("ball");
ball.style.marginTop = "10px";

moveButton.addEventListener("click",function (){

   ball.style.marginTop = parseInt(ball.style.marginTop) + 10 + "px";

})

#ball{
  width:20px;
  height:20px;
  border-radius:50%;
  background-color:black;
}

<button id="moveButton">Move Button</button>
<div id="ball"></div>