binary search

const binarySearch = (arr, ele) => {
    let start = 0
    let end = arr.length - 1
    let mid = Math.floor((start + end)/2)
    while(ele !== arr[mid] && start <= end) {
        if(ele < arr[mid]) end = mid - 1
        else start = mid + 1
        mid = Math.floor((start + end)/2)
    }
    return arr[mid] === ele ? mid : -1
}
binarySearch([1,2,6,3,9,10,43,90], 90)