For example if you need a random zip code you simply use:
and you get a random number with the characteristics of a zip code. The same for
but notice that these aren't necessarily "real" in the sense that the zip code or the phone number might not actually exist, they simply fit the pattern for the type of data so that you can feed them to a function that is supposed to work with them.
To use it all you have to do is include the library, about 5Kbytes minified and zipped, and start using it. It creates a global chance object but you can also create additional chance objects and initialize the seed for the random number generator so to produce a repeatable pseudo-random sequence. It works in the browser or with Node.js.
As well as generating text and formatted data types, it also has some random generators for primitive types - Boolean, character, integer and so on and, yes there is a dice!
Although the library is quite young, it has a good collection of advanced generators. For example, it will generate random sentences, paragraphs, names, domains, email addresses, postal addresses, time stamps, credit card numbers and, my own favorite, don't ask why, random GUIDs. For a full list of generators, see the Chance website.
The library is available under an Open Source MIT licence and there is lots of scope for adding additional generators. Given that each generator is small and fairly standalone it would make a good starting point for anyone wanting to get involved in a first open source project.