IF statements and comparing character strings

[Samohtvii]

I have tried everything to get a simple bit of code to work but nothing has worked.
pseudocode:
get user answer (yes/no)
if answer = yes
print yes

I always get the same error "Cannot assign to a named constant"
i have tried
--
t = LGT(answer, 'yes')
IF(t)
--
if(answer .eq. 'yes)
--
if(LGT(answer, yes))
--
and any other combination.

Please help
Thanks

 

[salgerman]

please post the entire code

 

[mazkime]

Comparisons in 'if' statements are made with '==', because '=' is used for assignments. Moreover, when comparing characters, the characters you are comparing to need to be given between quotes ('').

The following example works with my computer (gfortran) :

  program main
  implicit none
  character*3 :: answer

  answer = 'yes'

  if (answer == 'yes') then
    print*,'test successful'
  endif

  end program main

Hope it helps.

 

[mikrom]

This works too

if (answer .eq. 'yes') then
...

 

[Samohtvii]

Got it. Thanks guys.