binary-search.js

// Iterative function to implement Binary Search
let iterativeFunction = function (arr, x) {
  
    let start=0, end=arr.length-1;
         
    // Iterate while start not meets end
    while (start<=end){
 
        // Find the mid index
        let mid=Math.floor((start + end)/2);
  
        // If element is present at mid, return True
        if (arr[mid]===x) return true;
 
        // Else look in left or right half accordingly
        else if (arr[mid] < x) 
             start = mid + 1;
        else
             end = mid - 1;
    }
  
    return false;
}
  
// Driver code
let arr = [1, 3, 5, 7, 8, 9];
let x = 5;
  
if (iterativeFunction(arr, x, 0, arr.length-1))
    document.write("Element found!<br>");
else document.write("Element not found!<br>");
  
x = 6;
  
if (iterativeFunction(arr, x, 0, arr.length-1))
    document.write("Element found!<br>");
else document.write("Element not found!<br>");