<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
* {
margin: 0;
padding: 0;
} #demo {
width: 100px;
height: 100px;
/*position: absolute;*/
background-color: pink;
} </style>
</head>
<body>
<div id="demo" style="left:100px"></div>
</body>
</html>
<script>
var demo = document.getElementById("demo");
console.log(demo.offsetLeft); //打印出来的是0
console.log(demo.style.left); //打印出来的是100px </script>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
* {
margin: 0;
padding: 0;
} #father {
width: 200px;
height: 200px;
margin: 100px;/*不是到margin左侧的距离*/
padding: 50px;
border: 10px solid blue;
position: absolute;
background-color: pink;
} #son {
width: 50px;
height: 50px;
background-color: red;
}
</style>
</head>
<body>
<div id="father">
<div id="son"></div>
</div>
</body>
</html>
<script>
var son = document.getElementById("son");
console.log(son.offsetLeft); //打印出来是 50px;
</script>