Fortran77固定格式.f文件编译错误修复问询（无需额外编译选项）

报错原因 #

你的代码混用了Fortran90+的语法，且不符合.f后缀默认使用的Fortran77固定格式规范，具体问题如下：

• Fortran77固定格式要求可执行代码、声明代码必须从第7列开始编写，你代码中的implicit none、变量声明等行顶格编写，不符合格式要求
• 变量声明用的::是Fortran90引入的语法，纯Fortran77不支持该写法
• 变量choice未初始化就用在do while的判断条件中，运行时会出现随机行为
• 存在拼写笔误（退出提示里的progrm应为program）

修复后可正常编译运行的代码 #

program p1
      implicit none
      integer choice
      real inputValue
C     初始化choice为非0值，保证首次正常进入循环
      choice = 1

      do while(choice /= 0)
          print *, ' '
          print *, 'Enter a conversion option (1-6 or 0 to exit):'
          print *, '-------------'
          print *, '(1) Pounds to Kilograms'
          print *, '(2) Kilograms to Pounds'
          print *, '(3) Feet to meters'
          print *, '(4) Meters to feet'
          print *, '(5) farenheit to Celsius'
          print *, '(6) Celsius to Fahrenheit'
          print *, '(0) Exit this program'
          print *, '-------------'
          READ(*,*) choice

          IF (choice == 1) THEN
              print *, 'Please enter the number of Pounds to be converted into Kilograms'
              READ(*,*) inputValue
              inputValue  = inputValue / 2.20
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 2) THEN
              print *, 'Please enter the number of Kilograms to be converted into Pounds'
              READ(*,*) inputValue
              inputValue = inputValue * 2.20
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 3) THEN
              print *, 'Please enter the number of Feet to be converted into Meters'
              READ(*,*) inputValue
              inputValue = inputValue / 3.28
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 4) THEN
              print *, 'Please enter the number of Meters to be converted into Feet'
              READ(*,*) inputValue
              inputValue = inputValue * 3.28
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 5) THEN
              print *, 'Please enter the number of Fahrenheit to be converted into Celsius'
              READ(*,*) inputValue
              inputValue = (5.0/9.0) * (inputValue - 32)
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 6) THEN
              print *, 'Please enter the number of Celsius to be converted into Fahrenheit'
              READ(*,*) inputValue
              inputValue = (inputValue * 9.0/5.0) + 32
              print *, 'Your value is:', inputValue
          ELSE IF (choice == 0) THEN
              print *, 'EXIT'
          END IF
      ENDDO
      end

内容的提问来源于stack exchange，提问作者user12577766