binary example in javascript

let arr = [22,33,44,55,66,77,89]
let cc = 33;
let start = 0
let end = arr.length-1;
let position = undefined
while(start<=end){

let middle = Math.floor((start+end)/2);
if(arr[middle] === cc){
position = middle;
break;
}
else if(arr[middle]<cc){
start = middle+1
}else{
end = middle -1
}

}

console.log(position)