to mark the end of loop
t = ( double ) System . nanoTime ( ) - t ; System . out . println ( " sum ▁ is : ▁ " + Double . toString ( sum ) ) ; System . out . println ( " time ▁ taken ▁ by ▁ normal ▁ loops : " + Double . toString ( t / Math . pow ( 10.0 , 9.0 ) ) ) ; } }