Java基础---方法重载、重写

1、方法的重载：

方法名字相同、参数个数、类型不同

作用：同一个方法可以有多个用途

package study;

public class FuLei {
	public int zhenqian() {
		
		return 100000;
	}
	/**
	 * eat方法：
	 * @param food
	 */
	public void eat(String food) {
		System.out.println("在吃" + food);
	}
	
	/**
	 * eat方法的重载
	 * @param food
	 * @param weight
	 */
	public void eat(String food, int weight) {
		System.out.println("在吃" + food + "吃了" + weight + "斤");
	}
}

子类：

package study;

public class ZiLei extends FuLei{
	//重写父类的挣钱zhengqian方法
	@Override
	public int zhenqian() {
		
		return 1000000;
	}
}

运行

package study;

public class Yunxing {
	public static void main(String[] args) {
		FuLei fuLei = new FuLei();
		ZiLei ziLei = new ZiLei();
		
		System.out.println(fuLei.zhenqian());
		System.out.println(ziLei.zhenqian());
		
		ziLei.eat("dami");
		ziLei.eat("大米", 6);
	}
}

 

2.方法重写：

方法名字相同、参数个数类型相同

作用：继承、

package study;

public class FuLei {
	public int zhenqian() {
		
		return 100000;
	}
}

子类：

package study;

public class ZiLei extends FuLei{
	//重写父类的挣钱zhengqian方法
	@Override
	public int zhenqian() {
		
		return 1000000;
	}
}

main方法：

package study;

public class Yunxing {
	public static void main(String[] args) {
		FuLei fuLei = new FuLei();
		ZiLei ziLei = new ZiLei();
		
		System.out.println(fuLei.zhenqian());
		System.out.println(ziLei.zhenqian());
	}
}