79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
1.6 KiB
1.6 KiB
title, id, challengeType
| title | id | challengeType |
|---|---|---|
| Fibonacci sequence | 597f24c1dda4e70f53c79c81 | 5 |
Description
Write a function to generate the nth Fibonacci number.
///The nth Fibonacci number is given by : ///
Fn = Fn-1 + Fn-2
///The first two terms of the series are 0, 1.
///Hence, the series is : 0, 1, 1, 2, 3, 5, 8, 13...
///Instructions
Tests
tests:
- text: <code>fibonacci</code> is a function.
testString: assert(typeof fibonacci === 'function', '<code>fibonacci</code> is a function.');
- text: <code>fibonacci(2)</code> should return a number.
testString: assert(typeof fibonacci(2) == 'number', '<code>fibonacci(2)</code> should return a number.');
- text: <code>fibonacci(3)</code> should return 1.")
testString: assert.equal(fibonacci(3),1,"<code>fibonacci(3)</code> should return 1.");
- text: <code>fibonacci(5)</code> should return 3.")
testString: assert.equal(fibonacci(5),3,"<code>fibonacci(5)</code> should return 3.");
- text: <code>fibonacci(10)</code> should return 34.")
testString: assert.equal(fibonacci(10),34,"<code>fibonacci(10)</code> should return 34.");
Challenge Seed
function fibonacci(n) {
// Good luck!
}
Solution
function fibonacci(n) {
let a = 0, b = 1, t;
while (--n > 0) {
t = a;
a = b;
b += t;
}
return a;
}