文档介绍：练习题】类的成员变量:请定义一个交通工具(Vehicle)的类,其中有:属性:速度(speed),体积(size)等等方法:移动(move()),设置速度(setSpeed(intspeed)),加速speedUp(),减速speedDown()()中实例化一个交通工具对象,并通过方法给它初始化speed,size的值,并且通过打印出来。另外,调用加速,减速的方法对速度进行改变。lassVehicle{privatedoublespeed;privatedoublesize;publicVehicle(){}publicVehicle(doublespeed,doublesize){ =speed; =size;}publicvoidsetSpeed(doublespeed){ =speed;}publicdoublegetSpeed(){ returnspeed;}publicvoidsetSize(doublesize){ =size;}publicdoublegetSize(){ returnsize;}publicdoublespeedUp(){ return(speed+10);}publicdoublespeedDown(){ return(speed-10);} publicstaticvoidmain(String[]args){ Vehicleh=newVehicle(,80); "这个车的速度是:"+()); "这个车的大小是:"+()); "加速后是:"+()); "减速后是:"+()); }练习题】构造方法编写Java程序,模拟简单的计算器。定义名为Number的类,其中有两个整型数据成员n1和n2,应声明为私有。编写构造方法,赋予n1和n2初始值,再为该类定义加(addition)、减(subtration)、乘(multiplication)、除(division)等公有成员方法,分别对两个成员变量执行加、减、乘、除的运算。在main方法中创建Number类的对象,调用各个方法,并显示计算结果。lassNumbei{ privatedoublen1; privatedoublen2; umbei(){} umbei(doublen1,doublen2){ =n1; =n2; } publicdoubleaddition(){ return(n1+n2); } publicdoublesubtration(){ return(n1-n2); } publicdoublemultiplication(){ return(n1*n2); } publicdoubledivision(){ return(n1/n2); } publicstaticvoidmain(String[]args){ Numbeih=newNumbei(24,25); "两数之和是:"+()); "两数之差是:"+()); "两数之积是:"+());