2023年石化盈科笔试题.pdf

1.程序执行成果是什么.

publicclassEncapsulation{

classClassValue{

publicinti=15;

}

publicstaticvoidmain(String[]args){

//TODOAuto-generatedmethodstub

Encapsulationt=newEncapsulation();

t.first();

}

publicvoidfirst(){

ClassValuecv=newClassValue();

second(cv);

System.out.println(.println(+cv.i);

}

publicvoidsecond(ClassValuev){

ClassValuecv=newClassValue();

v.i=25;

v=cv;

System.out.println(.println(+v.i);

}

}

2.程序输出成果是什么

classA{

publicvoidshow(){

System.out.println(.println();

}

}

classBextendsA{

publicvoidshow(){

System.out.println(.println();

}

}

publicclassInherit{

/**

*@paramargs

*/

publicstaticvoidmain(String[]args){

Aa=newB();

if(ainstanceofA){

System.out.println(.println();

}

if(ainstanceofB){

System.out.println(.println();

}

}

}

3.程序输出成果是什么

publicclassPolymorphic{

/**

*@paramargs

*/

publicstaticvoidmain(String[]args){

//TODOAuto-generatedmethodstub

Parentpare=newSub();

pare.show();

}

}

classParent{

publicvoidshow(){

System.out.println(.println();

}

}

classSub