In Fortran 90, variable and function names must start with a letter. It may only use letters, digits, and the underscore. The underscore should be used to separate words in long names to improve clarity. OK, different name Names can have a maximum length of 31 characters. It is a good practice to use lots of comments in the source code.
Comments help the programmer easily see the purpose of various segments of code.
REALs have an exponential form. Back to Top Character Declarations Character variables are declared in a similar way to numeric types. The following operators are valid for numeric expressions. TRUE ., F . For example, multiplication has precedence over addition.