If, Else, While

Nim has many different control flow constructs, including the standard ifs, elses, and whiles. However, Nim does not use an else if construct like many languages, it uses a more condensed elif.

When inside a loop, continue can be used to skip the rest of the loop body and to begin the next iteration; break can be used to immediately leave the loop body.

Along with its other uses, the block statement can be used to create a label so that it’s possible to break out of nested loops.

import strutils, random

let answer = rand(10)
while true:
  echo "I have a number from 1 to 10, what is it? "
  let guess = parseInt(stdin.readLine)

  if guess < answer:
    echo "Too low, try again"
  elif guess > answer:
    echo "Too high, try again"
    echo "Correct!"

block busyloops:
  while true:
    while true:
      break busyloops