JAVASCRIPT

binary search in js

function binarySearch(sortedArray, key){
    let start = 0;
    let end = sortedArray.length - 1;

    while (start <= end) {
        let middle = Math.floor((start + end) / 2);

        if (sortedArray[middle] === key) {
            // found the key
            return middle;
        } else if (sortedArray[middle] < key) {
            // continue searching to the right
            start = middle + 1;
        } else {
            // search searching to the left
            end = middle - 1;
        }
    }
	// key wasn't found
    return -1;
}

binary search in js

function binarySearch(arr, val) {
  let start = 0;
  let end = arr.length - 1;

  while (start <= end) {
    let mid = Math.floor((start + end) / 2);

    if (arr[mid] === val) {
      return mid;
    }

    if (val < arr[mid]) {
      end = mid - 1;
    } else {
      start = mid + 1;
    }
  }
  return -1;
}

Binary Search Algorithm in javascript

function binarySearch(array, element) {
    let firstIndex = 0;
    let lastIndex = array.length - 1;
    let middleIndex = Math.floor((firstIndex + lastIndex) / 2);

    while (array[middleIndex] !== element && firstIndex <= lastIndex) {
        if(array[middleIndex] > element) {
                lastIndex = middleIndex - 1;
        }else {
                firstIndex = middleIndex + 1;
        }
        middleIndex = Math.floor((firstIndex + lastIndex) / 2);
    }
    return array[middleIndex] === element ? middleIndex : -1;
}

const array = [2, 3, 6, 8, 10, 12];
binarySearch(array, 8); // OutPut -> 3

JS binary search

// JavaScript program to implement recursive Binary Search
  
// A recursive binary search function. It returns
// location of x in given array arr[l..r] is present,
// otherwise -1
function binarySearch(arr, l, r, x){
    if (r >= l) {
        let mid = l + Math.floor((r - l) / 2);
  
        // If the element is present at the middle
        // itself
        if (arr[mid] == x)
            return mid;
  
        // If element is smaller than mid, then
        // it can only be present in left subarray
        if (arr[mid] > x)
            return binarySearch(arr, l, mid - 1, x);
  
        // Else the element can only be present
        // in right subarray
        return binarySearch(arr, mid + 1, r, x);
    }
  
    // We reach here when element is not
    // present in array
    return -1;
}
  
let arr = [ 2, 3, 4, 10, 40 ];
let x = 10;
let n = arr.length
let result = binarySearch(arr, 0, n - 1, x);
(result == -1) ? document.write( "Element is not present in array")                   : document.write("Element is present at index " +result);

js binary search

function binarySearch(arr, val) {
  let start = 0;
  let end = arr.length - 1;

  while (start <= end) {
    let mid = Math.floor((start + end) / 2);

    if (arr[mid] === val) {
      return mid;
    }

    if (val < arr[mid]) {
      end = mid - 1;
    } else {
      start = mid + 1;
    }
  }
  return -1;
}

binary search javascript

const arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30];


const binarySearch = (arr, x , start=0, end=arr.length) => {
  if(end < start) return -1;
  
  let mid = Math.floor((start + end) / 2);
  
  if(arr[mid] === x) return mid;

  if(arr[mid] < x) return binarySearch(arr, x, mid+1, end);
  
  else return binarySearch(arr, x , start, mid-1);
}

console.log(arr[binarySearch(arr,8)]);

binary search in js

function binarySearch(sortedArray, key){
    let start = 0;
    let end = sortedArray.length - 1;

    while (start <= end) {
        let middle = Math.floor((start + end) / 2);

        if (sortedArray[middle] === key) {
            // found the key
            return middle;
        } else if (sortedArray[middle] < key) {
            // continue searching to the right
            start = middle + 1;
        } else {
            // search searching to the left
            end = middle - 1;
        }
    }
	// key wasn't found
    return -1;
}