Question

The following program print 1 for 100E-2 and gives 0 for 100*10**(-2), that means that
the operator exponent doesnot work for negative **, is that correct.
Thanks in advance

program testme

implicit none

print*,100E-2

print*,100*10**(-2)

end program

Answer 1

You’ll notice that the second print statement prints 0 — no decimal pt, etc. Eg, integer zero. That’s because 10 by itself is an integer literal, and raising that to the negative 2 power correctly gives zero; multiplying it by integer 100 still gives integer zero.

If you instead use

print*,100*10.**(-2)

you’ll get the answer you expect.

The issue doesn’t arise with 100e-2 because any number expressed with scientific notation is a floating point (real) literal.