Language basics and statements

Nim uses indentation for blocks. Prefer let for immutable bindings, var for mutable state, and const for compile-time constants.

let name = "Nim"
var count = 0
const bufferSize = 4096
count += 1

Define procedures with proc:

proc greet(name: string): string =
  "Hello, " & name & "!"

Use if/elif/else, for, and while as expected. 1..5 includes the end and 0..<5 excludes it.

for number in 1..5:
  if number mod 2 == 0:
    echo number

Model data with enum, object, and sequences:

type
  Status = enum pending, running, completed
  Article = object
    title: string
    tags: seq[string]

let article = Article(title: "Nim", tags: @["language", "native"])

Export a module symbol with * and import it elsewhere:

# mathutil.nim
proc double*(value: int): int = value * 2

See the type and memory guide and official manual for the detailed model.