50 lines
1.2 KiB
Plaintext
50 lines
1.2 KiB
Plaintext
Calling an overridable method from a constructor could result in failures or strange behaviors when instantiating a subclass which overrides the method.
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For example:
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* The subclass class constructor starts by calling the parent class constructor.
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* The parent class constructor calls the method, which has been overridden in the child class.
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* If the behavior of the child class method depends on fields that are initialized in the child class constructor, unexpected behavior (like a ``++NullReferenceException++``) can result, because the fields aren't initialized yet.
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== Noncompliant Code Example
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----
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public class Parent
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{
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public Parent()
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{
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DoSomething(); // Noncompliant
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}
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public virtual void DoSomething() // can be overridden
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{
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...
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}
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}
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public class Child : Parent
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{
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private string foo;
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public Child(string foo) // leads to call DoSomething() in Parent constructor which triggers a NullReferenceException as foo has not yet been initialized
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{
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this.foo = foo;
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}
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public override void DoSomething()
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{
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Console.WriteLine(this.foo.Length);
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}
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}
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Comments And Links
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(visible only on this page)
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include::comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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