While Iterating through ArrayList using for loop instead of Iterator, why does the output reference an address instead of actual object?

Question

I've created a list from objects from my user defined class called students.

class Student {
    String name, phone, group;

    Student(String name, String phone, String group) {
        this.name = name;
        this.phone = phone;
        this.group = group;
    }
}

And accessed it in the following way:

public static void main(String[] args) {
        Student s1 = new Student("Ayush", "9841293412", "L1N1");
        Student s2 = new Student("Rahul", "9842432423", "L1M1");
        Student s3 = new Student("Gaurav", "984129231", "L1N2");

ArrayList<Student> al = new ArrayList<Student>();
    al.add(s1);
    al.add(s2);
    al.add(s3);
    al.add(s4);
    al.add(s5); 

   for(Student name:al){
       System.out.println("Name: " + name);
    }

But the output is referencing object like following:

Name: Student@1baf61
Name: Student@b5272

I don't know why this has happened.

Answer 1

Just extract the name field instead:

class Student {
    String name, phone, group;

    Student(String name, String phone, String group) {
        this.name = name;
        this.phone = phone;
        this.group = group;
    }

    public String getName() {
        return name;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", phone='" + phone + '\'' +
                ", group='" + group + '\'' +
                '}';
    }

    public static void main(String[] args) {
        Student s1 = new Student("Ayush", "9841293412", "L1N1");
        Student s2 = new Student("Rahul", "9842432423", "L1M1");
        Student s3 = new Student("Gaurav", "984129231", "L1N2");

        ArrayList<Student> al = new ArrayList<Student>();
        al.add(s1);
        al.add(s2);
        al.add(s3);

        for (Student name : al) {
            System.out.println("Name: " + name.name);
            System.out.println("Name: " + name.getName()); // Using a getter
            System.out.println(name); // Using toString
        }
    }
}

As a best practice use a getter or a toString implementation to better represent your model

Answer 2

You can override the toString method in your StudentClass or if u want only the name you can implement a getter method in your StundentClass..

class Student {
    String name, phone, group;

    Student(String name, String phone, String group) {
        this.name = name;
        this.phone = phone;
        this.group = group;
    }

    public String getName() {
        return name;
    }

    

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", phone='" + phone + '\'' +
                ", group='" + group + '\'' +
                '}';
    }

usage toString

for(Student name:al){
    System.out.println("Name: " + name);
}

output:

Name: Student{name='Ayush', phone='9841293412', group='L1N1'}

Name: Student{name='Rahul', phone='9842432423', group='L1M1'}

Name: Student{name='Gaurav', phone='984129231', group='L1N2'}

usage of your getter

for(Student name:al){
    System.out.println("Name: " + name.getName());
}

output:

Name: Ayush

Name: Rahul

Name: Gaurav