binary search

gistfile1.js

var find = function(arr, key) {
    if (arr.length < 1) {
        return null;
    }
    
    var low = 0,
        high = arr.length - 1,
        middle;
    
    while(high >= low) {
        middle = Math.floor((low + high) / 2);
        //console.log(low, middle, high);
        value = arr[middle];
        if (value == key) {
            return middle;
        } else if (value < key) {
            low = middle + 1;
        } else {
            high = middle - 1;
        }
    }
    return -1;
}

why not value === key?