JavaScript for...in 循环
JavaScript for...in 语句循环遍历对象的属性。
<!DOCTYPE html> <html> <body> <p>点击下面的按钮，循环遍历对象 "person" 的属性。</p> <button onclick="myFunction()">点击这里</button> <p id="demo"></p> <script> function myFunction() { var x; var txt=""; var person={fname:"Bill",lname:"Gates",age:56}; for (x in person) { txt=txt + person[x]; } document.getElementById("demo").innerHTML=txt; } </script> </body> </html>