Cacher is the code snippet organizer for pro developers

function binarySearch(items, value){

    var startIndex  = 0,
        stopIndex   = items.length - 1,
        middle      = Math.floor((stopIndex + startIndex)/2);

    while(items[middle] != value && startIndex < stopIndex){

        //adjust search area
        if (value < items[middle]){
            stopIndex = middle - 1;
        } else if (value > items[middle]){
            startIndex = middle + 1;
        }

        //recalculate middle
        middle = Math.floor((stopIndex + startIndex)/2);
    }

    //make sure it's the right value
    return (items[middle] != value) ? -1 : middle;
}

// Only works on sorted lists
var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];
var names = ['Ava', 'Elise', 'Enzo', 'Jessica', 'Michael'];