isOnline() when runned in browser environment, then returns online status, when runned in nodejs then returns null

isEmpty(value) returns true if either the argument is null or undefined

isNotEmpty(value) returns true if neither the argument is null nor undefined

isBrowser() return if the current environment is browser or not

isString(value), isFunction(value), isNumber(value), isUndefined(value), isNull(value), isObject(value), isBoolean(value)