源代碼
點擊運行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>教程</title> </head> <body> <script> var person; var car="Volvo"; document.write(person + "<br>"); document.write(car + "<br>"); var car=null document.write(car + "<br>"); </script> </body> </html>
運行結果