Constants

  1. const (
  2.     pi    = 3.14
  3.     world = '世界'
  4. )
  6. println(pi)
  7. println(world)

Constants are declared with const. They can only be defined at the module level (outside of functions).

Constant values can never be changed.

V constants are more flexible than in most languages. You can assign more complex values:

  1. struct Color {
  2.     r int
  3.     g int
  4.     b int
  5. }
  7. fn rgb(r int, g int, b int) Color {
  8.     return Color{
  9.         r: r
  10.         g: g
  11.         b: b
  12.     }
  13. }
  15. const (
  16.     numbers = [1, 2, 3]
  17.     red     = Color{
  18.         r: 255
  19.         g: 0
  20.         b: 0
  21.     }
  22.     // evaluate function call at compile-time
  23.     blue    = rgb(0, 0, 255)
  24. )
  26. println(numbers)
  27. println(red)
  28. println(blue)

Global variables are not allowed, so this can be really useful.

  1. println('Top cities: $top_cities.filter(.usa)')