what is the difference between ++x and x++

Answer 1

++x sums one and returns x, x++ returns x and THEN sums one

Answer 2

++x means x+1=x,, increment is performed first then value is assigned
x++ means x=x+1,, value is assigned first then increment is performed..

Answer 3

With objects you have to notice that post increment creates (often) an unnecessary copy of the object. This might affect the performance. Smart compilers however optimize this.