cpp / beginner
Snippet
The Scope Resolution Operator
The :: operator accesses items from specific scopes. Use namespace::item to reach a namespaced variable, or ::variable to access the global scope. This allows precise control over which variable you intend to use when names might conflict.
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cpp
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#include <iostream>int value = 100;namespace Outer {int value = 200;namespace Inner {int value = 300;void print() {std::cout << "Inner: " << value << std::endl;std::cout << "Outer: " << Outer::value << std::endl;std::cout << "Global: " << ::value << std::endl;}}}int main() {Outer::Inner::print();std::cout << "Direct Outer: " << Outer::value << std::endl;std::cout << "Direct Global: " << ::value << std::endl;return 0;}
Breakdown
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::value
The leading :: accesses the global scope variable
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Outer::value
Accesses 'value' inside the Outer namespace
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Outer::Inner::print()
Navigates through nested namespaces to call a function
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std::cout << "Inner: " << value
Inside Inner, unqualified 'value' refers to Inner::value