DaniWeb Forum Index > Software Development > C++

C++ RSS

About the namespaces

Please support our C++ advertiser: Intel Parallel Studio Home

•

Join Date: Aug 2004

Posts: 6

Reputation: vivekgalatage is an unknown quantity at this point

Solved Threads: 0

vivekgalatage vivekgalatage is offline

Offline

Newbie Poster

About the namespaces

Aug 3rd, 2004

Hello Everyone

can anyone please explain me about the concept of namespaces?

Regards

•

Join Date: Apr 2004

Posts: 4,362

Reputation: Dave Sinkula has a brilliant future

Solved Threads: 242

Dave Sinkula Dave Sinkula is offline

Offline

long time no c

Re: About the namespaces

Aug 3rd, 2004

•

Originally Posted by vivekgalatage

can anyone please explain me about the concept of namespaces?

Doing a search is your best bet for general queries.

"One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand

•

Join Date: Jun 2004

Posts: 436

Reputation: Chainsaw is an unknown quantity at this point

Solved Threads: 10

Chainsaw

Offline

Unprevaricator

Re: About the namespaces

Aug 3rd, 2004

General idea:

You know how you can enclose something inside braces and it is only visible inside the braces? Like:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
{
    int i;  // visible only inside the braces
}
i = i + 1; // i isn't seen, or isn't the one in the braces.
{
    int i;  // visible only inside the braces
}
i = i + 1; // i isn't seen, or isn't the one in the braces.

That's called a variable's 'scope'
Well, namespaces allow you to NAME a scope, like this:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
namespace Chainsaw
{
    int i;
};
 
{
    int i;
    i = 0;  // this is the 'i' declared inside THIS scope
    Chainsaw::i = 0; // this is the 'i' declared inside the Chainsaw name space scope
}
namespace Chainsaw
{
    int i;
};

{
    int i;
    i = 0;  // this is the 'i' declared inside THIS scope
    Chainsaw::i = 0; // this is the 'i' declared inside the Chainsaw name space scope
}

Think of them as 'named globals', almost as if they belonged to a struct. But a namespace is not a description of things (like a struct would be), it is an implementation of things. That is, the Chainsaw::i was declared as a variable inside the namespace just as if it were a global variable.

•

Join Date: Aug 2004

Posts: 3

Reputation: TITAN is an unknown quantity at this point

Solved Threads: 0

TITAN

Offline

Newbie Poster

Re: About the namespaces

Aug 3rd, 2004

•

Originally Posted by vivekgalatage

Hello Everyone

can anyone please explain me about the concept of namespaces?

Regards

I`ll try.
std is a namespace, and std::cout, refers to the object in std called cout.
So you can define an object called cout, without breaking the one definition rule. For example: In a large program, many programmers work together, and the possebility for several programmer have defined object with the same name, is huge. So if every programmer(or a programmer group) have defines a namespace, it doesn`t matter if several programmers have define the same name on several object`s as long as it`s in a namespace.

Edit: oops, I didn`t see the other threads.