java基础学习笔记——静态初始化块，初始化块，构造函数的执行顺序

代码：

// 数字即表示执行顺序
class A {
    String filed = func("5: filed of A");

    static String staticFiled = func("1: static filed of A");

    {
        func("6: code block of A");
    }

    static {
        func("2: static code block of A");
    }


    A() {
        func("7: constructor of A");
    }

    static String func(String message) {
        System.out.println(message);
        return message;
    }
}

class B extends A {

    {
        func("8: code block of B");
    }

    static {
        func("3: static code block of B");// 接着是子类static file和static代码块
    }

    B() {
        func("10: constructor of B");
    }

    String filed = func("9: filed of B");

    static String staticFiled = func("4: static filed of B");
}


public class Test1 {
    public static void main(String[] args) {
        B b = new B();
    }
}

输出：

1: static filed of A
2: static code block of A
3: static code block of B
4: static filed of B
5: filed of A
6: code block of A
7: constructor of A
8: code block of B
9: filed of B
10: constructor of B

总结

1. static file和static代码块谁在前谁先执行
2. filed和代码块谁在前谁先执行
3. 构造函数最后执行

参考：

Java的初始化块、静态初始化块、构造函数的执行顺序及用途探究