Should I buy Samsung Galaxy S3? Suggestions?

[♫ ♫ musical♫ ♫]

Im thinking to buy new phone, and Samsung Galaxy S3 fits me, but my friend has this phone and the battery dies in one day! he uses facebook, camera and music alot trough out the day, but why the battery is so weak? This is my first smartphone, so dont laugh... if you have this kind of phone, can you tell me how long your battery lasts? Thanks!
My friend charges over night and gets 100% before school and 3% before going to bed, if that helps...
He keeps full brightness

[Zian]

ermm yea if u charge over night it get 100% and it gets something around 20-10% before u go to sleep so i dnt think ur supposed to have a problem.its a gr8 smartfon and u can get it.umm and incase if ur having problem den u can always buy a battery casing .it is lyk n external battery,once ur fons battery charge is finished ,it will use the external casing battery.and if u think its complicated ,u can get a motorolla razr max hd.Its got the most powerfull battery andthe charge stays for a long tym 3tyms thes3 hope this helps and dont bother abt the english mistakes

[advanced phantom]

Then buy nexus 4. It's a phone with better hardware than SGS3 with a better design. The phone has a 4.7 inch screen and it has some similarities with SGS3. The 16 Gb version costs 349$ and it is better than SGS3. It runs latest android operating system. 4.2 jelly bean. It has a 2100mAh battery. But it's processor saves 40% more than other Q cores. And screen doesn't use much power like S3's super amoled. Or buy a motorola Razr Maxx HD with 3300mAh battery. And do some Internet research. It will give you some Idea. Don't do anything by listening to what other people say. Find out yourself on Internet.