如果constructor里调用了一个成员方法，这个方法被子类override了，当初始化一个子类实例时，父类的构造函数被的调用，此时父类构造函数的上下文里调用的成员方法，是父类的实现还是子类的实现？
你能不用运行代码，就能准确说出这些语句会打印什么出来呢？

ABAP

class ZCL_SUPER definition
  public
  create public .
public section.
  methods CONSTRUCTOR .
  methods SET_I
    importing
      !IV_I type INT4 .
protected section.
private section.
  data MV_SUPER type INT4 .
ENDCLASS.
CLASS ZCL_SUPER IMPLEMENTATION.
  method CONSTRUCTOR.
    me->set_i( 100 ).
  endmethod.
  method SET_I.
    me->mv_super = iv_i.
  endmethod.
ENDCLASS.
class ZCL_SUB definition
  public
  inheriting from ZCL_SUPER
  final
  create public .
public section.
  methods PRINT .
  methods SET_I
    redefinition .
protected section.
private section.
  data MV_SUB type I value 1 ##NO_TEXT.
ENDCLASS.
CLASS ZCL_SUB IMPLEMENTATION.
  method PRINT.
    WRITE: / ' sub:' , mv_sub.
  endmethod.
  METHOD set_i.
    super->set_i( iv_i = iv_i ).
    me->mv_sub = iv_i.
    WRITE: / 'mv_sub assigned by: ' , iv_i.
  ENDMETHOD.
ENDCLASS.

测试：

NEW zcl_sub( )->print( ).

测试结果：sub: 1

Java

public class SuperClass {

    private int mSuperX;

    public SuperClass() {
        setX(99);
    }

    public void setX(int x) {
        mSuperX = x;
    }
}
public class SubClass extends SuperClass {

    private int mSubX = 1;

    public SubClass() {}

    @Override
    public void setX(int x) {
        super.setX(x);
        mSubX = x;
        System.out.println("SubX is assigned " + x);
    }

    public void printX() {
        System.out.println("SubX = " + mSubX);
    }
}

test:

public static void main(String[] args) {
        SubClass sc = new SubClass();
        sc.printX();
    }

测试结果：

JavaScript

function SuperClass(){
    this.setX(99);
}

SuperClass.prototype = {
    mSuperX : 0,
    setX : function(x){
         this.mSuperX = x;
    }
};
function SubClass(){  
    SuperClass.call(this);  
    this.mSubX = 1;
}  

SubClass.prototype = new SuperClass();  

SubClass.prototype.setX = function(x){
        SuperClass.prototype.setX(x);
        this.mSubX = x;
        console.log("SubX is assigned " + x);
};

SubClass.prototype.print = function(){
    console.log("SubX: " + this.mSubX);
}

test:

var sub = new SubClass();
sub.print();

测试结果:

详细分析在我的SAP community博客里: A reminder for using constructor in OO world

ABAP 的一大特色

report z.

INCLUDE ole2incl.

DATA: ole   TYPE ole2_object,

      voice TYPE ole2_object,

      text  TYPE string.

text = 'With the advent of ES6 (referred to as ES2015 from here on), which not only made promises native to the language without requiring one of the countless available libraries,'

&& 'we also got generators. Generators have the ability to pause execution' &&

'within a function, which means that by wrapping them in a utility function, ' &&

'we have the ability to wait for an asynchronous operation to finish before' &&

' moving on to the next line of code. Suddenly your asynchronous code could' &&

' start to look synchronous!'.

DATA: it_tline TYPE STANDARD TABLE OF tline.

CREATE OBJECT voice 'SAPI.SpVoice'.

CALL METHOD OF voice 'Speak' = ole

   EXPORTING #1 = text.

*

用的也是很老的OLE技术：

report代码直接call的MS的sound engine，通过sapi.dll暴露出来，

这个report只是call了dll里其中一个speak方法：