源代码
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>享学课堂</title> </head> <body> <p id="demo"></p> <script> var x1 = {}; var x2 = ""; var x3 = 0; var x4 = false; var x5 = []; var x6 = /()/; var x7 = function(){}; document.getElementById("demo").innerHTML = "x1: " + typeof x1 + "<br>" + "x2: " + typeof x2 + "<br>" + "x3: " + typeof x3 + "<br>" + "x4: " + typeof x4 + "<br>" + "x5: " + typeof x5 + "<br>" + "x6: " + typeof x6 + "<br>" + "x7: " + typeof x7 + "<br>"; </script> </body> </html>
运行结果