1.编写一个类Calculator,有两个属性num1,num2,这两个数据的值，不能在定义的同时初始化，最后实现加减乘 除四种运算.
2.设计一个包含多个构造函数的类，并分别用这些构造函数来进行实例化对象。
3.实现交换两个变量的值。要求：需要交换实参的值
代码：
1.
import java.util.Scanner;
class Calculator{
private int num1;
private int num2;
public int getNum1() {
return num1;
}public void setNum1(int num1) {
this.num1 = num1;
}public int getNum2() {
return num2;
}public void setNum2(int num2) {
this.num2 = num2;
}
public int add(int num1,int num2){
return num1+num2;
}
public int difference(int num1,int num2){
return num1-num2;
}
public int product(int num1,int num2){
return num1*num2;
}
public double quotient(int num1,int num2){
return num1*1.0/num2;
}
}public class HomeWork{
public static void main(String[] args) {
System.out.println("请输入两个整数： ");
Calculator calculator = new Calculator();
Scanner scanner = new Scanner(System.in);
calculator.setNum1(scanner.nextInt()) ;
calculator.setNum2(scanner.nextInt());
System.out.println(calculator.add(calculator.getNum1(), calculator.getNum2()));
System.out.println(calculator.difference(calculator.getNum1(), calculator.getNum2()));
System.out.println(calculator.product(calculator.getNum1(), calculator.getNum2()));
System.out.println(calculator.quotient(calculator.getNum1(), calculator.getNum2()));
}
}【类和对象代码练习】2.
class Person{
private int age;
private String name;
public Person(){}
public Person(int age, String name){
this.age = age;
this.name = name;
}public void show(){
System.out.println("age: " + age + " name: " + name);
}public int getAge() {
return age;
}public void setAge(int age) {
this.age = age;
}public String getName() {
return name;
}public void setName(String name) {
this.name = name;
}
}public class HomeWork{
public static void main(String[] args) {
Person person = new Person();
person.setAge(17);
person.setName("ys");
person.show();
Person person1 = new Person(18, "ysa");
person1.show();
}
}3.
public class HomeWork{
public static void swap(int[]arr){
int tmp = arr[0];
arr[0] = arr[1];
arr[1] = tmp;
}
public static void main(String[] args) {
int[] array = {12,23};
System.out.println("array[0]= " + array[0] + "arr[1]= " + array[1]);
swap(array);
System.out.println("array[0]= " + array[0] + "arr[1]= " + array[1]);
}
}
