Julia Programming Projects

Learning about functions

Before we get to write our first full-fledged Julia program, the web crawler, we need to take yet another important detour. It's the last one, I promise.

As our code becomes more and more complex, we should start using functions. The REPL is great for exploratory programming due to its quick input-output feedback loop, but for any non-trivial piece of software, using functions is the way to go. Functions are an integral part of Julia, promoting readability, code reuse, and performance.

In Julia, a function is an object that takes a tuple of values as an argument and returns a value:

julia> function add(x, y) 
           x + y 
       end 
add (generic function with 1 method) 

There's also a compact assignment form for function declaration: ...