fortran中定义常数型变量

 

fortran中定义常数型变量

 

001、

[root@localhost test]# ls
test01.f90
[root@localhost test]# cat test01.f90
program test01_fortran

        implicit none

        integer :: a = 5
        integer, parameter :: b = 5       ## 定义一个常数型变量

        a = 10

        print *, "a = ", a

end program test01_fortran
[root@localhost test]# gfortran test01.f90 -Wall -O2 -o kkk
[root@localhost test]# ls
kkk  test01.f90
[root@localhost test]# ./kkk
 a =           10

 。

 

002、

[root@localhost test]# ls
test01.f90
[root@localhost test]# cat test01.f90
program test01_fortran

        implicit none

        integer :: a = 5
        integer, parameter :: b = 5

        a = 10
        b = 10                                    ## 尝试对常数型变量进行修改，无法编译

        print *, "a = ", a

end program test01_fortran
[root@localhost test]# gfortran test01.f90 -Wall -O2 -o kkk
test01.f90:9:8:

    9 |         b = 10
      |        1
Error: Named constant ‘b’ in variable definition context (assignment) at (1)

 。