When dynamic memory allocation is used extensively memory leak may occur.It happens when first memory block is not deleted . However the address is lost because the pointer contains the address of second block.The memory leak is unintentional occupied memory. It can de avoided by using delete statement.
example:
float *ptr new float
*ptr 6.0;//Access first block
'Use delete statement -- delete ptr ;Otherwise it will cause memory leak
ptr new float
*ptr 7.0//Acess second block