Re: C++ interview question - C / C++ / MFC Discussion Boards

Re: C++ interview question

Cedric Moonen1-Jul-09 22:02

Cedric Moonen

1-Jul-09 22:02

minkowski wrote:
nextChar() != '\0'

This part of the code actually "returns" something (true or false). You then assign the result of the comparison into the ch variable. true is usually 1 and false is 0. So, your character will contain either 0 or 1. If you try to ouptut as it is (so, without the casting to an integer), you will end up printing the character whose value is 0 or 1 (so, not printable character), that's why you need to cast it to an integer.

I guess that having a body for your function was not really important for the interview question: they simply have a function that returns a character...

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: C++ interview question

minkowski1-Jul-09 22:17

minkowski

1-Jul-09 22:17

Hi ya,

Thanks for your reply. Yes as you correctly said the answer is 0 or 1. I got confused because of the lack of function definition.

Can I ask how it is possible that you can use the != operator without being enclosed in a statement that expects true / false ? e.g. while() , if()

Thanks for any information.

Re: C++ interview question

CPallini1-Jul-09 22:19

CPallini

1-Jul-09 22:19

minkowski wrote:
Can I ask how it is possible that you can use the != operator without being enclosed in a statement that expects

!= is a binary operator that may be used in any expression.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

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Re: C++ interview question

_AnsHUMAN_ 1-Jul-09 22:04

_AnsHUMAN_

1-Jul-09 22:04

Yes you should get a linker error, due to the missing function definition

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

Re: C++ interview question

molesworth1-Jul-09 22:32

molesworth

1-Jul-09 22:32

Most interview questions just use code fragments, and you're supposed to assume functions exist in other libraries (that's generally spelled out in the interview).

Mind you, this is a very simple example question and probably meant as a warm up, not actually a real test. You should see the kinds of questions we ask in our interviews (although coding tests are only a small part of them).

There are three kinds of people in the world - those who can count and those who can't...

Re: C++ interview question

minkowski1-Jul-09 22:37

minkowski

1-Jul-09 22:37

Hi ya,

Thanks for your post, was wondering if you could put up some of your interview code questions?

Smile | :)

Re: C++ interview question

molesworth1-Jul-09 23:35

molesworth

1-Jul-09 23:35

LOL - I wouldn't be allowed to do that, just in case anyone reading here comes in for an interview (which is quite possible) Big Grin | :-D

There are three kinds of people in the world - those who can count and those who can't...

Re: C++ interview question

CPallini1-Jul-09 22:14

CPallini

1-Jul-09 22:14

minkowski wrote:
I said it would not compile since there is no definition (only a declaration) of the function nextChar()

Your point is correct (please note, however, that you would get a linker error, not a compiler one).

Now suppose nextChar is defined, somewhere (it's actual implementation doesn't matter).

minkowski wrote:
but the answer was 0 or 1. I am not sure why and also how can you use the != operator outside a if or while statement (i.e. something that expects true or false ?

nextChar() != '\0';

the above expression evaluates true whenever nextChar return a value different from '\0', false otherwise. Since true is 1 [^] (false is 0) an implicit cast from bool to char (that is an integer type) happens and you get ch=1 (or ch=0).
Smile | :)

BTW Are you that Minkowski [^]? Big Grin | :-D

Re: C++ interview question

toxcct1-Jul-09 22:57

toxcct

1-Jul-09 22:57

CPallini wrote:
W Are you that Minkowski [^]?

or that one[^] ?!

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Re: C++ interview question

minkowski1-Jul-09 23:10

minkowski

1-Jul-09 23:10

Ha ha, nope I am not that Minkowski although that was quite a story !

Smile | :)

Re: C++ interview question

CPallini1-Jul-09 23:15

CPallini

1-Jul-09 23:15

I was awaiting for some geometry hints... Big Grin | :-D

Re: C++ interview question

UserNameless1-Jul-09 23:30

UserNameless

1-Jul-09 23:30

CPallini wrote:
I was awaiting for some geometry hints...

shhhh. dont' tell anyone, but i'm letting it leak out - a triangle... has 3 sides. shhh. don't let anyone know though

Re: C++ interview question

CPallini1-Jul-09 23:42

CPallini

1-Jul-09 23:42

UserNameless wrote:
a triangle... has 3 sides.

That's the reason geometry is soooo difficult to grasp: triangle => three sides...while plain common sense would suggest triangle => three angles, or, at least, triside => three sides. Unsure | :~

Re: C++ interview question

minkowski2-Jul-09 1:43

minkowski

2-Jul-09 1:43

so it should be a quad - right - angle for a rectangle ?

Smile | :)

Re: C++ interview question

«_Superman_»1-Jul-09 22:15

«_Superman_»

1-Jul-09 22:15

minkowski wrote:
ch = nextChar() != '\0';

This is what the question is aiming at.
It's a matter of operator precedence.

«_Superman_»
I love work. It gives me something to do between weekends.

[Message Deleted]

npbzy1-Jul-09 21:13

npbzy

1-Jul-09 21:13

[Message Deleted]

Re: Need help in C++ progamming to output measurement automatically after manually defined points

CPallini1-Jul-09 21:25

CPallini

1-Jul-09 21:25

Dear Sir (or Madam), you're supposed to be a software developer.
Software developers are supposed to develop code.
At least developers are supposed to read forum guidelines [^] before posting here.
Smile | :)

[Message Deleted]

npbzy1-Jul-09 22:12

npbzy

1-Jul-09 22:12

[Message Deleted]

Re: Need help in C++ progamming to output measurement automatically after manually defined points

CPallini1-Jul-09 22:20

CPallini

1-Jul-09 22:20

Sorry, today's is not the Lazy Developer Day... Roll eyes | :rolleyes:

How to Use Regular Expression

Pavan_Putra1-Jul-09 20:23

Pavan_Putra

1-Jul-09 20:23

Hi..I have an regular expression "^[a-zA-Z0-9_]([^@ ]*)@[a-zA-Z0-9]{2,}((\\.[a-zA-Z0-9]{2,}))*$" for Email Validation in java.I want same to do in VC++ , is there ant way to do it...?

Plz help..!!!!

thanks in Advance.

It's not enough to be the best, when you have capability to be great....

Re: How to Use Regular Expression

Garth J Lancaster1-Jul-09 20:46

Garth J Lancaster

1-Jul-09 20:46

have a look at Boost Regex

http://www.boost.org/doc/libs/1_39_0/libs/regex/doc/html/index.html[^]

(there are other libraries out there to do the same)

'g'

Re: How to Use Regular Expression

«_Superman_»1-Jul-09 20:53

«_Superman_»

1-Jul-09 20:53

You just about beat me to it. Smile | :)

«_Superman_»
I love work. It gives me something to do between weekends.

Re: How to Use Regular Expression

Garth J Lancaster1-Jul-09 20:56

Garth J Lancaster

1-Jul-09 20:56

yeah - funny isnt it - sometimes I see a post and no-one's answered it, an Im thinking someone's just about to push the 'Post' button .. and then sometimes, on a very rare occasion, its me

'g'

Re: How to Use Regular Expression

«_Superman_»1-Jul-09 20:47

«_Superman_»

1-Jul-09 20:47

Use the boost library.
Look into Boost.Regex[^].

«_Superman_»
I love work. It gives me something to do between weekends.

Re: How to Use Regular Expression

Jijo.Raj1-Jul-09 20:51

Jijo.Raj

1-Jul-09 20:51

Hello Pavan,

This link will be helpful - Use regular expression in your C++ program[^].

Regards,
Jijo.

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