在Java中混淆调用方法(Confusing calling method in Java)
class Parent
{
private void method1()
{
System.out.println("Parent's method1()");
}
public void method2()
{
System.out.println("Parent's method2()");
method1();
}
}
class Child extends Parent
{
public void method1()
{
System.out.println("Child's method1()");
}
}
class test {
public static void main(String args[])
{
Parent p = new Child();
p.method2();
}
}
我很迷惑为什么在调用method1（）时会在Parent :: method2（）中调用Parents method1（）而不是Childs method1？ 我发现只有当method1（）是私有的时候才会发生这种情况。 有人可以解释我为什么吗？ 谢谢。
class Parent { private void method1() { System.out.println("Parent's method1()"); } public void method2() { System.out.println("Parent's method2()"); method1(); } } class Child extends Parent { public void method1() { System.out.println("Child's method1()"); } } class test { public static void main(String args[]) { Parent p = new Child(); p.method2(); } }I'm confuse why does in Parent::method2() when invoking method1() it will cal Parents method1() and not Childs method1 ? I see that this happens only when method1() is private? Can someone explain me why ? Thanks you.
最满意答案
这发生在范围规则的基础上; 在Parent中， method1的最佳匹配是类本地私有版本。
如果要将method1定义为public或Parent protected并在Child重写该方法，则调用method2将调用Child的method1 。
This happens based on scoping rules; in Parent the best match for method1 is the class-local private version.
If you were to define method1 as public or protected in Parent and override the method in Child, then calling method2 would invoke Child's method1 instead.
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