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<!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>