Clojure: Prefix notation
As you may have noticed, in popular programming languages, a function call looks something like f(arg1, arg2, arg3), but Clojure, like other Lisp-like languages, uses prefix notation (Polish notation). This notation style may seem awkward at first sight, but with a nested call, the convenience of this approach becomes apparent (it will take some time to get used to it). For example, a nested function call for an addition, subtraction and multiplication (yes, mathematical operations are functions too!) looks like this:
(+
1
(- 2 3)
(* 4 5 6)
(+ 7 8 9 10 11 12))
If you format the Clojure code carefully, it is easy to read, especially if the function call goes for more than two arguments. It is also worth noting that enumerating elements does not require commas, but they can be written, Clojure accepts both variants.
(+ 1 2 3) ; => 6
(+ 1, 2, 3) ; => 6
Instructions
Print the following expression to the standard output stream (using the println function): 1 + 10 - 2 * 7.
The exercise doesn't pass checking. What to do? 😶
If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:
- Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨
Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.
My code is different from the teacher's one 🤔
It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.
In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.
I've read the lessons but nothing is clear 🙄
It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.
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