If I upgrade to IOS 7 on my iPhone, will I loose all of my data and apps?

I want to know if I would loose any of this. Would I have to back up my iPhone and iCloud everything? Please let me know before I upgrade to the new system!

No it shouldn't

No bro it won't happpeeenn calm down

DO YOU KNOW THAT you can make up to $250 daily? It's absolutely free and you get instant $15 once registered.see for your self http://megastoon.com/?share=128121 I make $850 last month and it was sent to my PM account, if it work for me it can work for you too try it you will thank me later, trust me on this.

There's no harm in doing a backup before an update, especially to a major iOS release, however there would be no data loss during an update.