console 命令行工具 X clear

console

var box = document.querySelector(".box");
//.box的left值为0.9,但box.offsetLeft的值却是１,由此可见,box.offsetLeft取的值是个四舍五入的值。
console.log(box.offsetLeft);

//注意:当left的值取值为小数时,也是可以体现出小数部分的像素的

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JS Bin</title>
</head>
<body>
  <div class="cover">
    <div class="box"></div>    
  </div>
</body>
</html>

* {
  margin: 0;
  padding: 0;
}
.cover {
  position: relative;
  width:100px;
  height: 100px;
  background-color: blue;
}
.box {
  position:absolute;
  left: 0.9px;
  width: 100px;
  height: 100px;
  background-color: red;
}