Answers for questions from Stackoverflow http://stackoverflow.com/questions/39260085/how-to-get-all-values-out-of-array-and-its-sub-arrays http://stackoverflow.com/questions/27266550/how-to-flatten-nested-array-in-javascript

flatNestedArray.js

    var result = [];

    function isArray (value) {
        return value.constructor === Array;
    }

    function extract (value) {  

        if (isArray(value)) {
            value.forEach(function (each) {
                if (isArray(each)) extract(each);
                else result.push(each);
                });
        } else result.push(value);
    
        return result;
    }

    console.log(extract([["a", 2, [3, "mn"], "bu"], "la", [12, 34, "ab"]]));