After my iphone4 was restarted and turned off, my address book, text messages and photos all disappeared. But the phone is still there recently. Why ah! ! ! !

this will happen on an Apple phone with Contacts, SMS, photos and other switches turned on under iCloud.

When there are unexplained reasons in the cloud of Apple's mobile phone (which may be strong interference), the address book, text messages, photos, etc. in the mobile phone will disappear for a while, but the backup that is good in the cloud will not be deleted. In the case of good network connection, the system will automatically restore all the contents to the mobile phone synchronously, and in the case of bad network, the number of contacts will increase slowly until all the contacts are recovered.