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 definitionpubliccreate public .
public section.methods CONSTRUCTOR .methods SET_Iimporting!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 definitionpublicinheriting from ZCL_SUPERfinalcreate public .
public section.methods PRINT .methods SET_Iredefinition .
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() {}@Overridepublic 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