​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript 局部作用域</h1>
​
<p>myFunction() 之外的 carName 未定义。</p>
​
<p id="demo1"></p>
​
<p id="demo2"></p>
​
<script>
myFunction();
​
function myFunction() {
    var carName = "porsche";
    document.getElementById("demo1").innerHTML =
    typeof carName + " " + carName;
}
​
document.getElementById("demo2").innerHTML =
typeof carName;
</script>
​
</body>
</html>
​