代码示例:(标识:eg_js_scope_global)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript 全局作用域</h1>

<p>可以从任何脚本或函数中访问全局变量。</p>

<p id="demo"></p>

<script>
var carName = "porsche";
myFunction();

function myFunction() {
    document.getElementById("demo").innerHTML =
    "I can display " + carName;
}
</script>

</body>
</html>
运行结果: