Friend function: Difference between revisions

Revision as of 09:27, 1 February 2016

Revision as of 09:27, 1 February 2016

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Normally, a [[function (computer science)|function]] that is defined outside of a class cannot access such information. Declaring a function a '''friend''' of a class allows this, in languages where the concept is supported.

A friend function is declared by the class that is granting access, explicitly stating what function from a class is allowed access. A similar concept is that of [[friend class]].you may also kno that you

Friends should be used with caution. Too many functions or external classes declared as friends of a class with protected or private data may lessen the value of [[separation of concerns|encapsulation]] of separate classes in object-oriented programming and may indicate a problem in the overall architecture design. Generally though, friend functions are a good thing for encapsulation, as you can keep data of a class private from all except those who you explicitly state need it, but this does mean your classes will become tightly coupled.