Good morning! Here's our prompt for today.

Implement a function that returns the Fibonnaci number for a given integer input. In a Fibonacci sequence, each number is the sum of the two preceding ones.

The simplest is the series: 1, 1, 2, 3, 5, 8, etc.

This is because:

1fibonacci(0) = 0
2fibonacci(1) = 1
3fibonacci(2) = 1
4fibonacci(3) = 1 + 1 = 2
5fibonacci(4) = 1 + 2 = 3
6fibonacci(5) = 2 + 3 = 5

So if we were to invoke fibonacci(5), we'd want to return 5 (because the second to last number was 2 + last number was 3).

Constraints

• The value of n will always be a non negative integer and <=40
• The answer is guaranteed to fit in the integer data type
• Expected time and space complexity are both O(n)

Try to solve this here or in Interactive Mode.

How do I practice this challenge?

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  console.log('PASSED: ' + '`fibonacci(34)` should return `5702887`');

var assert = require('assert');

​

/*

 * @param {number} n The Fibonacci number to get.

 * @returns {number} The nth Fibonacci number

 */

​

function fibonacci(num) {

  // fill this in

  return num;

}

​

try {

  assert.equal(fibonacci(1), 1);

​

  console.log('PASSED: ' + '`fibonacci(1)` should return `1`');

} catch (err) {

  console.log(err);

}

​

try {

  assert.equal(fibonacci(17), 1597);

​

  console.log('PASSED: ' + '`fibonacci(17)` should return `1597`');

} catch (err) {

  console.log(err);

}

​

try {

Here's how we would solve this problem...

How do I use this guide?