JavaScript: Binary search using recursion

Last update on May 30 2022 10:08:18 (UTC/GMT +8 hours)

JavaScript Function: Exercise-8 with Solution

Write a JavaScript program for binary search.

Sample array : [0,1,2,3,4,5,6]
console.log(l.br_search(5)) will return '5'

Pictorial Presentation:

JavaScript: Binary search using recursion

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Binary search using recursion</title>
</head>
<body>

</body>
</html>

JavaScript Code:

Array.prototype.br_search = function (target) 
{
  var half = parseInt(this.length / 2);
  if (target === this[half]) 
  {
    return half;
  }
  if (target > this[half]) 
  {
    return half + this.slice(half,this.length).br_search(target);
  } 
  else
  {
    return this.slice(0, half).br_search(target);
  }
};

l= [0,1,2,3,4,5,6];

console.log(l.br_search(5));

Output:

Flowchart:

Live Demo:

See the Pen javascript-recursion-function-exercise-8 by w3resource (@w3resource) on CodePen.

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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