无法更改Java对象中的方法变量

Question

我在更改联系人对象中的变量值时遇到问题。我正在尝试制作一个联系人列表，但我无法更改变量trach方法的值。我有editTouch方法调用change eName方法，这两个方法都传递了ArrayList对象trach引用，所以它不应该在main方法中更改值trach ArrayList时出现问题，但问题是当我想更改对象的名称时它不会更改它。我这里缺少什么吗？

package telefonski_imenik;

public class Contact {
protected String name;
protected String lastname;
protected String number;

public Contact(String name, String lastname, String number) {
    setName(name);
    setLastName(lastname);
    setNumber(number);
}

public void setName(String name) {
    this.name = name;
}

public void setLastName(String lastname) {
    this.lastname = lastname;
}

public void setNumber(String number) {
    this.number = number;
}

public String getName() {
    return this.name;
}

public String getLastName() {
    return this.lastname;
}

public String getNumber() {
    return this.number;
}
}



package telefonski_imenik;
import java.util.ArrayList;
import java.util.Scanner;



 public class TelefonskiImenik {

public static void createContact(String ime, String prezime, String broj, ArrayList<Contact> 
 ContactList) {
    Contact noviKontakt = new Contact(ime, prezime, broj);
    ContactList.add(noviKontakt);
}

public static void editContact(ArrayList<Contact> ContactList) {
    
    System.out.println("Unesite nove podatke");
    changeName(ContactList);
    
    
}

public static void changeName(ArrayList<Contact> ContactList) {
    
    Scanner novinput = new Scanner(System.in);
    System.out.println("Unesite staro ime");
    String oldName = novinput.nextLine();
    System.out.println("Unesite novo ime");
    String newName = novinput.nextLine();
    
    for (int i = 0; i < ContactList.size(); i++) {
        if (ContactList.get(i).equals(oldName)) {
            ContactList.get(i).setName(newName);
        }
    }
    
    novinput.close();
}



public static void main(String[] args) {
    
    
    ArrayList<Contact> ContactList = new ArrayList<Contact>();
    
    Scanner input = new Scanner(System.in);
    
    System.out.println("Unesite podatke");
    String name = input.nextLine();
    String lastname = input.nextLine();
    String number= input.nextLine();
    
    createContact(name, lastname, number, ContactList);
    
    
    
    for (int i = 0; i < ContactList.size(); i++) {
        System.out.println(ContactList.get(i).getName());
        System.out.println(ContactList.get(i).getLastName());
        System.out.println(ContactList.get(i).getNumber());
    }
    
    
    editContact(ContactList);
    
    for (int i = 0; i < ContactList.size(); i++) {
        System.out.println(ContactList.get(i).getName());
        System.out.println(ContactList.get(i).getLastName());
        System.out.println(ContactList.get(i).getNumber());
    }
    
    input.close();
}

}

Answer 1

您忘记获取循环中对象的名称：

for (int i = 0; i < ContactList.size(); i++) {
        if (ContactList.get(i).equals(oldName)) {
            ContactList.get(i).setName(newName);
        }
    }

ContactList.get(i).getName().equals(oldName)