Maps and filters are typical for functional languages. A map is a function of the form map(func, coll), where func is a (often anonymous) function that is successively applied to every element of the coll collection, so map returns a new collection. Some examples are as follows:

Map can also be used with functions that take more than one argument. In this case, it requires a collection for each argument, for example, map(*, [1, 2, 3], [4, 5, 6]) works per element and returns [4, 10, 18].

When the function passed to map requires several lines, it can be a bit unwieldy to write this as an anonymous function. For instance, consider using the following function:

map( x-> begin
           if x == 0 return 0
           elseif iseven(x) return 2
           elseif isodd(x) return 1
           end
       end,[-3:3])

This function returns [1,2,1,0...