Fortran中parameter

在Fortran中，`parameter`关键字用于声明一个常量，该常量在程序运行时不能被修改。例如：

program example
  implicit none
  integer, parameter :: n = 10
  real :: x(n)
  
  x = 1.0    ! 将数组x的元素全部赋值为1.0
  
  write(*,*) 'The value of n is: ', n
  write(*,*) 'The value of x(1) is: ', x(1)
  
end program example

在上面的例子中，声明了一个常量`n`，其值为10，这个值在程序运行时不能被修改。在声明数组`x`时，使用了`n`作为数组的长度。在程序中，将数组`x`的所有元素赋值为1.0，并打印出`n`和`x(1)`的值。由于`n`是一个常量，所以它的值不能被修改。

相关问题

fortran中parameter用法

Fortran中的parameter关键字用于定义常量。它可以在程序中定义一个常量，这个常量的值在程序运行时不能被改变。parameter关键字通常用于定义数学常数、物理常数、数组大小等常量。例如：

parameter (pi = 3.1415926)
parameter (n = 100)

这里定义了一个名为pi的常量，它的值为3.1415926；还定义了一个名为n的常量，它的值为100。在程序中可以直接使用这些常量，例如：

area = pi * r**2
do i = 1, n
   ...
end do

Fortran parameter

In Fortran, a parameter is a named constant that is assigned a value that cannot be changed during the execution of the program. It is declared using the `parameter` keyword followed by the name of the constant and its value.

For example, consider the following code:

program example
  implicit none
  integer, parameter :: n = 10
  real, parameter :: pi = 3.14159
  print *, "The value of n is:", n
  print *, "The value of pi is:", pi
end program example

In this code, we have declared two parameters `n` and `pi`. The value of `n` is set to 10 and the value of `pi` is set to 3.14159. These values cannot be changed during the execution of the program.

When we run the program, it will print the following output:

The value of n is:           10
The value of pi is:   3.14159012    

Note that parameters are often used to define physical or mathematical constants that are used throughout the program. They can also be used to simplify the code and make it more readable by replacing hard-coded values with named constants.