Function commonPrefix

tests/test_code/js/moment/moment.js:2029–2038

(arr1, arr2)

        globalLocale;

    function commonPrefix(arr1, arr2) {
        var i,
            minl = Math.min(arr1.length, arr2.length);
        for (i = 0; i < minl; i += 1) {
            if (arr1[i] !== arr2[i]) {
                return i;
            }
        }
        return minl;
    }

    function normalizeLocale(key) {
        return key ? key.toLowerCase().replace('_', '-') : key;