噓~

1.function !key :don't change the imput

real,external ::aaa !this must be written in main program

real,intrinsic ::bbb

function aaa(a,b)

real aaa

end function

2.common !功能:share 記憶體 ;讀位子,不讀名稱, 值可被改變

paragram test

real aa

commom/tt1/aa

end

subroutine s1(x,aaa) !也可傳遞函數

real a1

common/tt1/a1   !here the value of a1 = the valus of aa in paragram

real,external::aaa

retun

end subroutine

black data

real aa

commom/tt1/aa

data aa/1.d0/

end block data

3.使變數永遠活著

integer,save ::aa

4.interface

case1. :傳陣列

case2. :傳遞參數個數有改(ex:有optional)

case3. :改變 傳遞參數的位置

case4. :傳入或回傳指標

5.recursive

    recursive function fact(n) result(ans)

    !result(ans) 用來存function fact的計算結果

    implicit none

    integer n !"n" is imput. You don't set "real fact" because ans is the result what you want.

    real ans !output

    !set the end point ,this is very important

    if (n<0) then

      ans=0

      write(*,*) "wrong n"

       return !終止遞迴

    else if (n==1) then

      ans=1

      return !終止遞迴

    end if

    ans=n*fact(n-1)

    return !終止function 並回傳計算結果

   end function