<html><head><style>#test { left: 100px; margin: 10px; padding: 10px; width: 300px; position: relative; border: 5px solid black}</style></head><body><div id="test"> <p>单击按钮获取测试 div 的 offsetLeft。</p> <p><button onclick="myFunction()">试一试</button></p> <p>offsetLeft is: <span id="demo"></span></p></div><script>function myFunction() { var testDiv = document.getElementById("test"); document.getElementById("demo").innerHTML = testDiv.offsetLeft;}</script></body></html>