java,构造函数，重载

class Tree {
	int height;
	Tree() {
		print("Planting a seedling");
		height = 0;
	}

	Tree(int i) {
		print("Creating new Tree that is "+ i + " feet tall");
		height = i;
	}

	public void plant() {
		print("Tree is " + height + " feet tall");

	}

	public void plant(String name) {
		System.out.println(s + ": Tree is "+ height + " feet tall");
	}

	static void print(String s) {
		System.out.println(s);
	}

}

public class OverLoading {
	public static void main(String[] args) {
		for (int i = 0;i < 5;i++) {
			Tree t = new Tree(5);
			t.plant();
			t.plant("OverLoading");
		}
		Tree t = new Tree();		
	}

}

  

     如果传入的实际参数类型“小于”方法中声明的形式参数类型,实际参数的类型就会被“提升”。char 型略有不同,如果无法找到恰好接受 char参数的方法,就会把 char 直接提升至 int 型。
    方法接受“较小”的基本类型作为参数。如果传入的实际参数“较大”,你就得在圆括号里写上类型名称,做必要的类型转换。如果不这样做,编译器就会报错.