功能：遍历对象的属性语法：for(variableinobject){}范例：varobj={a:1,b:2,c:3};for(keyinobj){console.log(key)//a,b,cconsole.log(obj[key])//1,2,3}
功能：遍历对象的属性语法：for(variableinobject){}范例：varobj={a:1,b:2,c:3};for(keyinobj){console.log(key)//a,b,cconsole.log(obj[key])//1,2,3}