【十日目】Java学習

Java学習10日目

1. 練習問題


class Animal {
public static void saySomething() {
System.out.print("Gurrr! ");
}
}
public class Cow extends Animal {
public static void saySomething() {
System.out.print("Moo! ");
}

public static void main(String[] args) {
Animal[] animals = {new Animal(), new Cow()};
for(Animal a : animals) {
a.saySomething();
}
}
}

実行結果:java Cow
Gurrr! Gurrr!



class Animal {
void saySomething() {
System.out.print("Gurrr! ");
}
}
public class Cow extends Animal {
protected void saySomething() {
System.out.print("Moo! ");
}

public static void main(String[] args) {
Animal[] animals = {new Animal(), new Cow()};
for(Animal a : animals) {
a.saySomething();
}
}
}


実行結果:java Cow
Gurrr! Moo!



class Animal {
static void x() {
System.out.print("Animal ");}
void y() { x(); }
}

class Cow extends Animal {
static void x() {
System.out.print("Cow ");}
void z() { x(); }
}

public class Main {
public static void main(String[] args) {
Cow obj = new Cow();
obj.y();
obj.z();
}
}

実行結果:>java Main
Animal Cow


class Foo {
void method(Object obj) {System.out.println("Object");}
void method(Number obj) {System.out.println("Number");}
void method(Integer obj) {System.out.println("Integer");}
void method(char[] obj) {System.out.println("char[] ");}
}

public class Main {
public static void main(String[] args) {
Foo foo = new Foo();
foo.method("Hello");
}
}

実行結果:java Main
Object


import java.util.*;