JavaScript: Get the first n Fibonacci numbers

Last update on May 30 2022 10:08:08 (UTC/GMT +8 hours)

JavaScript Function: Exercise-6 with Solution

Write a JavaScript program to get the first n Fibonacci numbers.

Note: The Fibonacci Sequence is the series of numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, . . . Each subsequent number is the sum of the previous two.

Pictorial Presentation:

JavaScript: Get the first n Fibonacci numbers

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Fibonacci Series</title>
</head>
<body>

</body>
</html>

JavaScript Code:

var fibonacci_series = function (n) 
{
  if (n===1) 
  {
    return [0, 1];
  } 
  else 
  {
    var s = fibonacci_series(n - 1);
    s.push(s[s.length - 1] + s[s.length - 2]);
    return s;
  }
};

 console.log(fibonacci_series(8));

Output:

[0,1,1,2,3,5,8,13,21]

Flowchart:

Live Demo:

See the Pen javascript-recursion-function-exercise-6 by w3resource (@w3resource) on CodePen.

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Next: Write a JavaScript program to check whether a number is even or not.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04