freeCodeCamp/curriculum/challenges/russian/08-coding-interview-prep/rosetta-code/factorial.russian.md

title, id, challengeType, forumTopicId, localeTitle

title	id	challengeType	forumTopicId	localeTitle
Factorial	597b2b2a2702b44414742771	5	302263	Факториал

Description

Напишите функцию для возврата факториала числа.

Факториал числа определяется:

п! = n * (n-1) * (n-2) * ..... * 1

Например: 3! = 3 * 2 * 1 = 6 4! = 4 * 3 * 2 * 1 = 24

Примечание: 0! = 1

Instructions

Tests

tests:
  - text: <code>factorial</code> is a function.
    testString: assert(typeof factorial === 'function');
  - text: <code>factorial(2)</code> should return a number.
    testString: assert(typeof factorial(2) === 'number');
  - text: <code>factorial(3)</code> should return 6.
    testString: assert.equal(factorial(3),results[0]);
  - text: <code>factorial(3)</code> should return 120.
    testString: assert.equal(factorial(5),results[1]);
  - text: <code>factorial(3)</code> should return 3,628,800.
    testString: assert.equal(factorial(10),results[2]);

Challenge Seed

function factorial(n) {
  // Good luck!
}

After Tests

const results=[6,120,3628800];

Solution

function factorial(n) {
  let sum = 1;
  while (n > 1) {
    sum *= n;
    n--;
  }
  return sum;
}