Memory Leaks and Bad memory usage

memory.m

//===================== Memory Leak===========================



NSString *str =[[NSString alloc]initwithFormate:@"Hello"];
UILabel *lbl=[[UILabel alloc]init];
lbl.text= str;
[str release];

UILabel *lbl2=[[UILabel alloc]init];
lbl2.text=str;           // Gives memory leak as str is released


//=====================Bad memory usage===========================

NSString *str =[[NSString alloc]initwithFormate:@"Hello"];
UILabel *lbl;
lbl.text= str;
 
    // bad memory usage as allocated string object is not released.