我是编程新手，这是我的第一门课程。我很难理解整个概念，希望能得到一些关于如何继续的提示。
基本上我需要编写一个简单的地址簿程序，让用户输入2个（或更多？）用户的信息。我的课程辅助给了我以下建议：
在我的应用程序（演示或测试）类的主要方法中 - 创建类AddressBook的两个或多个实例/对象 - 使用实例（对象）来调用AddressBook类的实例方法 - 使用2个实例/对象来比较他们的名字
我目前有以下内容：
AddressBook.java
import java.util.Scanner;
public class AddressBook {
Scanner sc = new Scanner(System.in);
//Declare method variables and initial value (empty)
String firstName = "";
String middleName = "";
String lastName = "";
String homeAddress = "";
String businessPhone = "";
String homePhone = "";
String cellPhone = "";
String skypeId = "";
String facebookId = "";
String personalWebSite = "";
public AddressBook(String firstName, String middleName,
String lastName, String homeAddress, String businessPhone,
String homePhone, String cellPhone, String skypeId,
String facebookId, String personalWebSite) {
this.firstName = firstName;
this.middleName = middleName;
this.lastName = lastName;
this.homeAddress = homeAddress;
this.businessPhone = businessPhone;
this.homePhone = homePhone;
this.cellPhone= cellPhone;
this.skypeId = skypeId;
this.facebookId = facebookId;
this.personalWebSite = personalWebSite;
}
//Setters
void setFirstName(String firstName) {
this.firstName = firstName;
}
void setMiddleName(String middleName) {
this.middleName = middleName;
}
void setLastName(String lastName){
this.lastName = lastName;
}
void setHomeAddress(String homeAddress) {
this.homeAddress = homeAddress;
}
void setBusinessPhone(String businessPhone) {
this.businessPhone = businessPhone;
}
void setHomePhone(String homePhone) {
this.homePhone = homePhone;
}
void setCellPhone(String cellPhone) {
this.cellPhone = cellPhone;
}
void setSkypeId(String skypeId) {
this.skypeId = skypeId;
}
void setFacebookId(String facebookId) {
this.facebookId = facebookId;
}
void setPersonalWebSite(String personalWebSite) {
this.personalWebSite = personalWebSite;
}
//Getters
public String getFirstName() {
System.out.print("First name: ");
String firstName = sc.nextLine();
return firstName;
}
public String getMiddleName() {
System.out.print("Middle name: ");
String middleName = sc.nextLine();
return middleName;
}
public String getLastName() {
System.out.print("Last name: ");
String lastName = sc.nextLine();
return lastName;
}
public String getHomeAddress() {
System.out.print("Home address: ");
String homeAddress = sc.nextLine();
return homeAddress;
}
public String getBusinessPhone() {
System.out.print("Business phone number: ");
String businessPhone = sc.nextLine();
return businessPhone;
}
public String getHomePhone() {
System.out.print("Home phone number: ");
String homePhone = sc.nextLine();
return homePhone;
}
public String getCellPhone() {
System.out.print("Cell phone number: ");
String cellPhone = sc.nextLine();
return cellPhone;
}
public String getSkypeId() {
System.out.print("Skype ID: ");
String skypeId = sc.nextLine();
return skypeId;
}
public String getFacebookId() {
System.out.print("Facebook ID: ");
String facebookId = sc.nextLine();
return facebookId;
}
public String getPersonalWebSite() {
System.out.print("Personal Website: ");
String personalWebSite = sc.nextLine();
return personalWebSite;
}
public String compareNames() {
String comp1 = name1.getFirstName;
String comp2 = name2.getFirstName;
if (comp1.equalsIgnoreCase(comp2)) {
System.out.println("The names match!");
} else {
System.out.println("The names don't match!");
}
}
} // end of class AddressBook
AddressBookDemo.java
public class AddressBookDemo {
public static void main(String[] args) {
// Create two AddreeBook objects
AddressBook name1 = new AddressBook();
AddressBook name2 = new AddressBook();
// Invoke methods on those objects
System.out.println("Enter the first person's info");
name1.getFirstName();
//Testing input/output
System.out.println(name1.firstName);
// name1.getMiddleName();
// name1.getLastName();
// name1.getHomeAddress();
// name1.getBusinessPhone();
// name1.getHomePhone();
// name1.getCellPhone();
// name1.getSkypeId();
// name1.getFacebookId();
// name1.getPersonalWebSite();
System.out.println("Enter the second person's info");
name2.getFirstName();
//Testing input/output
System.out.println(name2.firstName);
// name2.getMiddleName();
// name2.getLastName();
// name2.getHomeAddress();
// name2.getBusinessPhone();
// name2.getHomePhone();
// name2.getCellPhone();
// name2.getSkypeId();
// name2.getFacebookId();
// name2.getPersonalWebSite();
} // end of Main
} // End of class AddressBookDemo
正如您所看到的，我在尝试初始化类AddressBook（）的两个实例时遇到了构造函数错误。如果我尝试添加一个'null'的arg，我在调用方法后测试输出时只返回'null'。我还在main中创建了compareName（）方法但是还没有调用它，因为我甚至无法使第一部分工作。另外我有点困惑我应该如何将name1.firstName和name2.firstName的值发送回main（或者我应该只是将值存储到另一个变量中并在每次getFirstName（）时创建一个增量循环叫什么？）。
答案 0 :(得分：0)
在您的主要课程中，您需要传入您希望存储在地址簿中的值，即
double numberOfMinutes = 0.00;
double additionalMinutesCost = 0.60;
double totalCost = 0.00;
double cost = 0.00;
double extra = 0.00;
double teleCost = 2.50;
//Display banner
System.out.print("Welcome to Kenneth's Telephone Company\nBill Calculator\n\n");
//Promt user for minutes
System.out.print("Please enter the Amount of minutes: ");
numberOfMinutes = keyboard.nextDouble();
if (numberOfMinutes ==0) {
System.out.print("Amount due: $0\n\n");
System.out.print("Thank you for working with us\n");
} else {
//Check number of minutes
if(numberOfMinutes >=1 && numberOfMinutes <=3) {
System.out.println("Amount due: $2.50\n");
System.out.print("Thank you for working with us\n");
} else {
//Calculate additonal cost
extra = numberOfMinutes -3;
cost = additionalMinutesCost * extra;
totalCost = cost + teleCost;
System.out.printf("Amount due: $%.2f\n\n", totalCost);
System.out.println("Thank you for working with us");
}
}
这将使用上述信息设置AddressBook name1 = new AddressBook("firstName", "middleName",
"lastName", "homeAddress", "businessPhone",
"homePhone", "cellPhone", "skypeId",
"facebookId", "personalWebSite");
类型name1的新AddressBook。您可能还需要考虑创建类型为AddressBook的ArrayList，它将存储AddressBook类的许多实例。
ArrayList<AddressBook> myAddressBook = new ArrayList();
然后你需要将一个对象添加到ArrayList：
myAddressBook.add(new AddressBook(("firstName", "middleName",
"lastName", "homeAddress", "businessPhone",
"homePhone", "cellPhone", "skypeId",
"facebookId", "personalWebSite"));
答案 1 :(得分：0)
这是我最终使用这里给出的一些建议。我将坚持只有2个联系人，因为这是作业所要求的;
Addressbook.java
import java.util.Scanner;
public class AddressBook {
Scanner sc = new Scanner(System.in);
//Declare method variables and initial value (empty)
String firstName = "";
String middleName = "";
String lastName = "";
String homeAddress = "";
String businessPhone = "";
String homePhone = "";
String cellPhone = "";
String skypeId = "";
String facebookId = "";
String personalWebSite = "";
public String getFirstName() {
System.out.print("First name: ");
firstName = sc.nextLine();
return firstName;
}
public String getMiddleName() {
System.out.print("Middle name: ");
middleName = sc.nextLine();
return middleName;
}
public String getLastName() {
System.out.print("Last name: ");
lastName = sc.nextLine();
return lastName;
}
public String getHomeAddress() {
System.out.print("Home address: ");
homeAddress = sc.nextLine();
return homeAddress;
}
public String getBusinessPhone() {
System.out.print("Business phone number: ");
businessPhone = sc.nextLine();
return businessPhone;
}
public String getHomePhone() {
System.out.print("Home phone number: ");
homePhone = sc.nextLine();
return homePhone;
}
public String getCellPhone() {
System.out.print("Cell phone number: ");
cellPhone = sc.nextLine();
return cellPhone;
}
public String getSkypeId() {
System.out.print("Skype ID: ");
skypeId = sc.nextLine();
return skypeId;
}
public String getFacebookId() {
System.out.print("Facebook ID: ");
facebookId = sc.nextLine();
return facebookId;
}
public String getPersonalWebSite() {
System.out.print("Personal Website: ");
personalWebSite = sc.nextLine();
return personalWebSite;
}
} // end of class AddressBook
AddressBookDemo.java
public class AddressBookDemo {
public static void main(String[] args) {
// Create two AddreeBook objects
AddressBook name1 = new AddressBook();
AddressBook name2 = new AddressBook();
// Invoke methods on those objects
System.out.println("Enter the first person's info");
name1.getFirstName();
name1.getMiddleName();
name1.getLastName();
name1.getHomeAddress();
name1.getBusinessPhone();
name1.getHomePhone();
name1.getCellPhone();
name1.getSkypeId();
name1.getFacebookId();
name1.getPersonalWebSite();
System.out.println("Enter the second person's info");
name2.getFirstName();
name2.getMiddleName();
name2.getLastName();
name2.getHomeAddress();
name2.getBusinessPhone();
name2.getHomePhone();
name2.getCellPhone();
name2.getSkypeId();
name2.getFacebookId();
name2.getPersonalWebSite();
// Compare names
String comp1 = name1.firstName + " " + name1.middleName.toUpperCase().charAt(0) + ". " + name1.lastName;
String comp2 = name2.firstName + " " + name2.middleName.toUpperCase().charAt(0) + ". " + name2.lastName;
if (comp1.equalsIgnoreCase(comp2)) {
System.out.println("The names match!");
} else {
System.out.println("The names don't match!");
} // end if/else statement
} // end of Main
} // End of class AddressBookDemo
感谢大家的帮助！非常感谢。