Test your skills (2005)

[Hikaru79]

Java:

import java.util.*; public class OldArrayListTest {    public static void main(String[] args) {       ArrayList<String> a = new ArrayList<String>();       a.add("hello");       a.add("world");    } }

Like so?

[wtd]

Nope, but thanks for playing our game. The code I posted should compile without alteration.

[Hikaru79]

wtd wrote:

Nope, but thanks for playing our game. The code I posted should compile without alteration.

Oooh. I misread the question. You want the actual command used to compile it. In that case,

code:

javac -nowarn OldArrayListTest.java

There No more warning.

[wtd]

Hikaru79 wrote:

wtd wrote:

Nope, but thanks for playing our game. The code I posted should compile without alteration.

Oooh. I misread the question. You want the actual command used to compile it. In that case,

code:

javac -nowarn OldArrayListTest.java

There No more warning.

Not quite there yet. Turning off warnings is cheating.

[Hikaru79]

wtd wrote:

Not quite there yet. Turning off warnings is cheating.

Drat But it technically does do what you asked

How about this?

code:

javac -source 1.4 OldArrayListTest.java

[wtd]

Hikaru79 wrote:

wtd wrote:

Not quite there yet. Turning off warnings is cheating.

Drat But it technically does do what you asked

How about this?

code:

javac -source 1.4 OldArrayListTest.java

It's about time you figured it out.

[wtd]

O'Caml TYS:

Given a function "find" which takes a "'a list" and a "'a" and returns None if the list doesn't contain the specified element, and Some int indicating the position in the list if it does...

Take this code:

code:

match find some_list some_value with    | None -> print_endline "Not found"    | Some pos -> print_endline ("Found it at: " ^ string_of_int pos)

And modify it such that "Found it at: " becomes "Found it at even: " if the position is an even number. If it's odd, the message should remain the same as in the above code.

You may not use "if" or "else".

[wtd]

Haskell TYS:

Reimplement Haskell's zipWith function. Replicate all of zipWith's functionality and behaviors. To avoid ambiguity, call your function "myZipWith".

You may not use "if", "case", or "|", and your function should consume at most two lines.

[Cervantes]

wtd wrote:

O'Caml TYS:

Given a function "find" which takes a "'a list" and a "'a" and returns None if the list doesn't contain the specified element, and Some int indicating the position in the list if it does...

Take this code:

code:

match find some_list some_value with    | None -> print_endline "Not found"    | Some pos -> print_endline ("Found it at: " ^ string_of_int pos)

And modify it such that "Found it at: " becomes "Found it at even: " if the position is an even number. If it's odd, the message should remain the same as in the above code.

You may not use "if" or "else".

code:

match find some_list some_value with    | None -> print_endline "Not found"    | Some pos when pos mod 2 == 0 -> print_endline ("Found it at even: " ^ string_of_int pos)    | Some pos -> print_endline ("Found it at: " ^ string_of_int pos)

[wtd]

Ok smartguy...

Redefine List.map in terms of List.fold_left.

code:

let map f = ...

[Geminias]

I guess I'll give her a go:

1. Do you know what all of the different uses of "const" or "static" mean?

const prevents an initialized value from changing. It can also be used to specify that a method will not change any data in the class. It can also be used in a function/method to prevent a certain parameter from being reassigned.

static is either a containment specifier that allows you to tell the compiler to store a variable in global memory, or it is something else that I dont know what it is called but allows you to specify static members or functions of a class so that you can access them without an instance of that class and the data is accessible by all instances of this class.

2. Do you understand why a normal class can be split into a header and a ".cpp" source file, but a templated class cannot?

This is not true, you can #include "object.cpp" at the bottom of the header file to give the compiler information about the template.

3. Do you understand why you shouldn't use identifiers beginning with two underscores, even though it's technically legal?

Someone told me that system libraries and so forth use the __ prefix on some of their variables. Other than that I really don't know.

4. Do you understand the difference between:
c++ / ++c

the first increments c and returns c before the inc. second incs and returns inc value.

5. Do you understand why one of the following works and the other doesn't?

the const keyword on the "a" variable prevents a from being assigned. In the second code the initializer form is used which is allowed. The details of this are sketchy to me because I thought

constructor : initialize(someVal)

translated to: initialize = someVal.

to be continued... please give feedback in the meantime

[OneOffDriveByPoster]

wtd @ Wed Jan 12, 2005 7:16 pm wrote:

In conjunction with number 2, I need to return zero to indicate the program finished successfully.

No; not really. Some versions of GCC are buggy in that respect though (IIRC). (I am making the assumption that posting to old TYS threads with answers, etc. is not necroposting).