const
    /**
     * Getting raw object prototype
     * @param target {Object}
     * @return {String}
     */
    getPrototypeName = target => Object.prototype.toString.call(target),

    /**
     * Determines whether target exists or not
     * @param target {Object}
     * @return {boolean}
     */
    isset = target => !/(Undefined|Null)/.test(getPrototypeName(target)),

    /**
     * Check if target is Regular Expression
     * @param target {Object}
     * @return {boolean}
     */
    isFunction = target => /Function/.test(getPrototypeName(target)),

    /**
     * Check if target is function
     * @param target {Object}
     * @return {boolean}
     */
    isRegExp = target => /RegExp/.test(getPrototypeName(target)),

    /**
     * Check if target is string
     * @param target {Object}
     * @return {boolean}
     */
    isString = target => /String/.test(getPrototypeName(target)),

    /**
     * Check if target is number
     * @param target {Object}
     * @return {boolean}
     */
    isNumber = target => /Number/.test(getPrototypeName(target)),

    /**
     * Check if target is object
     * @param target {Object}
     * @return {boolean}
     */
    isObject = target => /Object/.test(getPrototypeName(target)),

    /**
     * Check if object is array
     * @param target {Object}
     * @return {boolean}
     */
    isArray = target => /Array/.test(getPrototypeName(target)),

    /**
     * Check if target is empty
     * @param target {Object}
     * @return {boolean}
     */
    empty = target => {

        // Objects
        if (isObject(target)) return  Object.keys(target).length === 0;

        // Strings
        if (isString(target)) return target.valueOf() === "";

        // Arrays
        if (isArray(target)) return  target.length === 0;

        // Other
        return false;
    },

    /**
     * Compare two objects
     * @param obj1 {Object}
     * @param obj2 {Object}
     * @return {boolean}
     */
    equals = (obj1, obj2) => {

        // Checking if variables can be compared
        if (!isset(obj1) || !isset(obj2)) return false;

        // Checking if objects are of the same type
        if (getPrototypeName(obj1) !== getPrototypeName(obj2)) return false;

        // Checking content equality
        switch (true) {

            // Comparing strings (class String covered)
            case isString(obj1): {
                return obj1.valueOf() === obj2.valueOf();
            }

            // Comparing arrays (strict order)
            case isArray(obj1): {
                // Checking size of arrays
                if (obj1.length !== obj2.length) return false;

                // Checking all items
                for (let i = 0; i < obj2.length; i++)
                    if (!equals(obj1[i], obj2[i])) return false;

                return true;
            }

            // Comparing objects
            case isObject(obj1): {
                // Checking size of arrays
                if (Object.keys(obj1).length !== Object.keys(obj2).length) return false;

                // Checking all items
                for (let key in obj1) { // Not checking null values of the keys
                    if (!obj2.hasOwnProperty(key) || !equals(obj1[key], obj2[key])) return false;
                }

                return true;
            }

            default: {
                return obj1 === obj2;
            }
        }
    };