C++中友元（友元函數和友元類）的用法和功能

時間 2020-05-14

標籤 c++ 函數用法功能欄目 C&C++ 简体版

原文原文鏈接

採用類的機制後實現了數據的隱藏與封裝，類的數據成員通常定義爲私有成員，成員函數通常定義爲公有的，依此提供類與外界間的通訊接口。可是，有時須要定義一些函數，這些函數不是類的一部分，但又須要頻繁地訪問類的數據成員，這時能夠將這些函數定義爲該函數的友元函數。除了友元函數外，還有友元類，二者統稱爲友元。友元的做用是提升了程序的運行效率（即減小了類型檢查和安全性檢查等都須要時間開銷），但它破壞了類的封裝性和

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1. C++友元的用法(友元函數、友元類和友元成員函數)
2. [C/C++] 友元函數和友元類
3. C++ 類(友元函數和友元類)
4. c++-友元函數和友元類
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