[Algorithms] Binary Search Algorithm using TypeScript

(binary search trees) which form the basis of modern databases and immutable data structures. Binary search works very much the way humans intuitively search for a name in a yellow pages directory (if you have ever seen one) or the dictionary.

In this lesson we learn how to implement a Binary Search Algorithm using TypeScript / Javascript, and we describe the problem that it solves.

function binarySearch(
array: number[],
element: number,
start: number = 0,
end: number= array.length -1
): number {

if(end < start) {
return -1;
}

const middle = Math.floor((start + end) / 2);
return element === array[middle]
? middle
: element < array[middle]
? binarySearch(array, element, start, middle - 1)
: binarySearch(array, element, middle + 1, end);
}

const unsortedArray = [ 6, 7, 8, 9, 10, 1, 2, 3, 4, 5]

console.log("Index of 4: ", binarySearch(unsortedArray.sort(), 4))
console.log("22 not found: ", binarySearch(unsortedArray.sort(), 22))