17 lines
655 B
HTML
17 lines
655 B
HTML
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<p>
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Virtual member functions are key to the object-oriented paradigm,
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such as making it easy for old code to call new code.
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A virtual function allows derived classes to replace the implementation
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provided by the base class. The compiler makes sure the replacement is
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always called whenever the object in question is actually of the derived class,
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even if the object is accessed by a base pointer rather than a derived pointer.
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This allows algorithms in the base class to be replaced in the derived class,
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even if users dont know about the derived class.
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<code>
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class A {
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public:
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virtual void foo() {}
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}
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</code>
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</p>
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