Java：先执行父类的构造函数，然后是引用对象的构造函数（必须有new声明实际类型），然后是自己的构造函数。
public class Test {public static void main(String[] args) {Child child = new Child();}}class Parent{Parent() {System.out.println("to construct Parent.");}}class Child extends Parent{Child() {System.out.println("to construct Child.");}Delegatee delegatee = new Delegatee();}class Delegatee {Delegatee(){System.out.println("to construct Delegatee.");}}
public class Test {public static void main(String[] args) {Child child = new Child();}}
class Parent{Parent() {System.out.println("to construct Parent.");}}
class Child extends Parent{Child() {System.out.println("to construct Child.");}Delegatee delegatee = new Delegatee();}
class Delegatee {Delegatee(){System.out.println("to construct Delegatee.");}}
结果是：
to construct Parent. to construct Delegatee. to construct Child.
而C#的构造函数执行顺序是：先引用对象，在父类，再子类。
using System;namespace ConsoleApplication1{public class Test {public static void Main(String[] args) {Child child = new Child();}}class Parent {public Parent() {Console.WriteLine("to construct parent");}}class Child : Parent {public Child() {Console.WriteLine("to construct Child.");}Delegatee delegatee = new Delegatee();}class Delegatee {public Delegatee() {Console.WriteLine("to construct Delegatee.");}}}
using System;namespace ConsoleApplication1{public class Test {public static void Main(String[] args) {Child child = new Child();}}
class Parent {public Parent() {Console.WriteLine("to construct parent");}}
class Child : Parent {public Child() {Console.WriteLine("to construct Child.");}Delegatee delegatee = new Delegatee();}class Delegatee {public Delegatee() {Console.WriteLine("to construct Delegatee.");}}}
to construct Delegatee. to construct Child. to construct Parent.
总结：被依赖的先构造，依赖于人的后构造。Java 是跨层依赖优先于同层依赖构造，而C#是同层依赖优先于跨层依赖。
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