Key ************* ************* Js object
******************** ********************************************************
*** Js object attributes '' can be added from time to increase
*** However, if a character with a special
*** ** must be added * Made-in-such as China **
*****
********************
give a chestnut:
var {Photo
size: 12 is,
}
************************************************** ***
**** photo.size equivalent to photo [ 'size']
Js object traversing
for (var key in photo) {
// value can not be obtained with photo.key
// so the engine will go to find the object key attribute
// key will not be treated as a variable
// photo can be used [key] but not with
// Photo [ 'Key']
}