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.