顶级对象BOM
Window
<!DOCTYPE html>
<html lang="en">
<head></head>
<body>
<script>
// 全局变量或函数, 都会变成window的属性或方法
var num = 10;
console.log(num);
console.log(window.num);
function fn() {
console.log(11);
}
fn();
window.fn();
alert(11);
window.alert(11);
var name = 10;
console.log(window.name);
console.dir(window);
</script>
</body>
</html>