How to read real numbers as characters

问题

I want to do some arithmetic operation to an array of real number and later I have to read it as an input for character variable. I used read statement still I get the error as

UNIT SPECIFICATION MUST BE AN INTEGER OR CHARACTER VARIABLE.

I also verified the format descriptor. Here is my piece of code

 real::la(10), sl
 integer::i
 character(len=5)::lat
 character(len=7)::station

 sl=11.25

 do i=1,10
   la = sl+ (i*0.25)
   read(la(i),'(F5.2)')lat
   station= lat//'xx'
 end do 

回答1:

When you have

read(la(i),'(F5.2)') lat

you are asking to read from the unit la(i) (external file) into the character variable lat. This isn't what you want, but is also wrong. This wrongness results in the error message you see: the unit number must be an integer.

However, correcting la to integer is not what you want to do.

Instead, you want to do an internal write to the character variable lat:

write(lat, '(F5.2)') la(i)

回答2:

The F5.2 format specifies that a real value is being read. lat is a a string of characters. The two are not compatible.

The simplest fix is to read to a variable that is real.

Alternative, change the format to A (indicating a string), then do an internal read from lat using the F5.2 format.

来源：https://stackoverflow.com/questions/29489920/how-to-read-real-numbers-as-characters