Solved

small question about pointer array

Posted on 2006-11-19
3
236 Views
Last Modified: 2010-04-01
     char* pszMonths[] ={"invalid",
                          "January",
                          "February",
                          "March",
                          "April",
                          "May",
                          "June",
                          "July",
                          "August",
                          "September",
                          "October",
                          "November",
                          "December",};


In this statement there are 12 pointers that points at 12 months. Every pointer has 4 bytes in memory. The thing i don't understand is:

Where are these strings stored in memory?

pszMonths[1] is the pointer that points at January. Let's say 0x111 is the address of "January" But how command do tell "store 'January' at 0x111 " ? Is it stored simultaneously with the pointer array? (sorry for my english)
0
Comment
Question by:data_grrr
  • 2
3 Comments
 
LVL 7

Accepted Solution

by:
UrosVidojevic earned 125 total points
ID: 17975828
The array you declared is an array of pointers to chars. Pointer to some object is actually its address (address of its first byte).

So basicly this is array of addresses of begginings of your strings, so elements of your array may look like this in memory:

pszMonths[0]   ---> 0x0400 and this is address of the first character of your first string.
pszMonths[1]   ---> 0x0700 and this is address of the first character of your second string.
...
pszMonths[12] ---> 0x1004 and this is address of the first character of your 12th string.

And memory looks like this:

0x0400 -> i
0x0401 -> n
0x0402 -> v
...
0x0700 -> J
...

The choice of addresses where compiler puts your strings is compiler's job so you don't need to worry about that.  Of course compiler tends to put your strings one after another without empty spaces between them in memory.

So it is very probbably that memory will look like this

i n v a l i d \0  J a n u a r y \0 F e b r u a r y...

Regards, U.V.
0
 
LVL 7

Expert Comment

by:UrosVidojevic
ID: 17975835
\0 is an character with ASCII code 0 that marks the end of some char array.
If you need more help, just say...
0
 
LVL 1

Author Comment

by:data_grrr
ID: 17975842
thanks, now i understand :)
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

C++ Properties One feature missing from standard C++ that you will find in many other Object Oriented Programming languages is something called a Property (http://www.experts-exchange.com/Programming/Languages/CPP/A_3912-Object-Properties-in-C.ht…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will be introduced to the technique of using vectors in C++. The video will cover how to define a vector, store values in the vector and retrieve data from the values stored in the vector.

914 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now