getCoherentNumbers() - returns blocks of coherent numbers in an array

getCoherentNumbers.js

/**
 * getCoherentNumbers([1,2,3,5,6,8,9,10])
 * 
 * returns [[1,2,3], [5,6], [8,9,10]]
 * 
 * Works only for increasing numbers, like 1 2 3 4, not 5,1,3,2,4
 */
var getCoherentNumbers = function getCoherentNumbers(arr) {
    var result = [];
    var tmpArray = [];
    for(var i = 0, l = Math.max.apply(null, arr); i < l; i++) {
        if(typeof arr[i] != "undefined" && typeof arr[i + 1] != "undefined") {
            if (arr[i] == (arr[i + 1] - 1)) {
                tmpArray.push(arr[i]);
            } else {
                tmpArray.push(arr[i]);
                result.push(tmpArray);
                tmpArray = [];
            }
        } else if(typeof arr[i] != "undefined" && typeof arr[i + 1] == "undefined") {
            if (arr[i - 1] == (arr[i] - 1)) {
                tmpArray.push(arr[i]);
                result.push(tmpArray);
            } else {
                if(typeof arr[i] != 'undefined') {
                    tmpArray.push(arr[i]);
                }
                result.push(tmpArray);
                tmpArray = [];
            }
        }
    }

    return result;
}