Count distinct items in an array

countDistinct.js

function countDistinct(items) {
    var result = [];
    for (var i = 0, l = items.length; i < l; ++i) {
        var item = items[i];
        var index = -1;
        for (var j = 0; j < result.length; ++j) {
            var existing = result[j];
            if (item === existing[0]) {
                index = j;
                break;
            }
        }
        if (index >= 0) {
            ++result[index][1];
        } else {
            result.push([item, 1]);
        }
    }
    return result;
}