What are namespaces used for

Question

i dont how they work but what are they used for

Answer 1

Namespaces are mostly used(as far as I know of) to have a variable name multiple times but with different declarations. This can also be usefull to group variables together.
Let me clearify:
use namespace std;
namespace test1
{
string var = "This variable is part of namespace test1";
}
int main()
{
int var = 10;
cout << var ;
// To access the namespace var use:
cout << test1::var ;
return 0;
}

Answer 2

Namespaces are used to prevent names clashes in large projects.
You can declare a foo() function two times, namespaces help you in this case.
App::foo();
Utility::foo();
Or if you declare a bar() function still present in a header you included..
namespace MyNames{
int rand(int range){
returns a int random number generated whit my algorithms
}
}
include<iostream.. ctime cstdio...
int main(){
int X = rand()%10;
int Y = MyNames::rand(10);