<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>效率测试</title>
</head>
<body>
</body>
<script>
function fn() {
var d1 = +new Date();
for ( var i = 0; i < 1000; i++ ) {
var div = document.createElement('div');
div.style.width = '100px';
div.style.height = '2px';
div.style.border = '1px solid red';
document.body.appendChild( div );
}
var d2 = +new Date();
console.log( d2 - d1 );
}
fn();
</script>
</html>