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<!DOCTYPE html> <html> <head> <meta charset="utf-8"> </head> <body> <p> typeof 操作符返回變量或表達(dá)式的類型。</p> <p id="demo"></p> <script> document.getElementById("demo").innerHTML = typeof "john" + "<br>" + typeof 3.14 + "<br>" + typeof false + "<br>" + typeof [1,2,3,4] + "<br>" + typeof {name:'john', age:34}; </script> </body> </html>