Main.java

import java.util.ArrayList;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);
        ArrayList<Student> students = new ArrayList<Student>();

        while (true) {
            System.out.print("name: ");
            String name = reader.nextLine();

            if (!(name.isEmpty())) {
                System.out.print("studentnumber: ");
                String studentNumber = reader.nextLine();

                students.add(new Student(name, studentNumber));
            } else {
                System.out.println("");
                break;
            }

        }
        for (Student student : students) {
            System.out.println(student.toString());
        }

        System.out.println("");
        System.out.print("Give search term: ");
        String search = reader.nextLine();

        for (Student student : students) {
            String name = student.getName();
            
            if (name.contains(search)) {
                System.out.println("Result:");
                System.out.println(student.toString());
            }
        }
    }
}

Student.java

public class Student {
    // variables
    private String name;
    private String studentNumber;
    
    // constructor
    public Student(String name, String number) {
        this.name = name;
        this.studentNumber = number;
    }
    
    // methods
    public String getName() {
        return this.name;
    }
    
    public String getStudentNumber() {
        return this.studentNumber;
    }
    
    public String toString() {
        return this.name + " (" + this.studentNumber + ")";
    }
}