Java - Enhanced for loop for ArrayList with custom object

Question

Given this StudentList Class with ArrayList that takes Student Object with three fields: Roll number, Name and Marks, how to write enhanced For Loop instead of the regular For Loop method as written in the code below?

Student.java

public class Student {
private int rollNumber;
private String name;
private int marks;

public Student(int roll, String name, int marks){
    this.rollNumber=roll;
    this.name=name;
    this.marks=marks;
}

public int getRollNumber(){
    return this.rollNumber;
}

public String getName() {
    return name;
}

public int getMarks() {
    return marks;
  }
}

Here is the SudentList Class with Main Method

StudentList.java

import java.util.ArrayList;
import java.util.List;

public class StudentList {
public static void main(String[] args) {

Student a = new Student(1, "Mark", 80);
Student b = new Student(2, "Kevin", 85);
Student c = new Student(3, "Richard", 90);

List<Student> studentList = new ArrayList<>();
studentList.add(a);
studentList.add(b);
studentList.add(c);

for (int i = 0; i < studentList.size(); i++) {
  System.out.println("Roll number: " + 
  studentList.get(i).getRollNumber() +
                ", Name: " + studentList.get(i).getName() + ", Marks: " + 
  studentList.get(i).getMarks());
    }
  }
}

for(Student student : studentList){// code} means for each student in studentList... — zlakad
– zlakad, Commented Feb 10, 2018 at 12:53

Suresh Atta · Accepted Answer · 2018-02-10 12:55:03Z

5

Instead of index, foreach gives you direct objects

for (Student st : studentList) {
       System.out.println("Roll number: " +  st.getRollNumber() + ", Name: " + st.getName() + ", Marks: " + st.getMarks());
    }

So whenever you see list.get() replace it with direct object reference and you are done.

edited Feb 10, 2018 at 12:55

answered Feb 10, 2018 at 12:50

Suresh Atta

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3 Comments

javaland235 Over a year ago

so in this case Java takes care of the studentList.get(i) part?

Suresh Atta Over a year ago

@Econ_newbie It works in a different by using Iterator. Read more at the link given

Basil Bourque Over a year ago

@Econ_newbie For details, see the Java Language Specification.

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