The most obvious way to store data is in plain data structures such as arrays and queues, or even a hashtable, but don’t forget these implicit ones:

• Call stack. As the name say, it’s a stack data structure. It saves the local variables before making another function call. This is often exploited in recursion to avoid passing around an explicit data structure
• Closures. What closure means is that when you create an anonymous function, the variables involved (other than the arguments) that is saved along (captured) with the function object you created. This can be exploited to make forward iterators or generators
• Functions. You can make a function that does nothing other than returning a certain piece of data. It’s an excellent way to make avoid the overhead of managing (reading, updating promptly) a config file. Works best when your programming language requires so little typing to specify data (such as MATLAB) that your code is almost as short as a plain text config file.