PPT Slide
write (unit = *, fmt = *) " Please enter a number whose square root is wanted. "
read (unit = *, fmt = *) Next_Datum
if (Next_Datum >= 0.0) then ! Choose "then" block or "else" block.
write (unit = *, fmt = *) sqrt( Next_Datum )
write (unit = *, fmt = *) " Can't find the square root of a negative number "