Java.util.Collections.frequency() in Java

// Java program to demonstrate 
// working of Collections.frequency()
import java.util.*;

public class GFG
{
    public static void main(String[] args)
    {
        // Let us create a list with 4 items
        ArrayList<String> list =
                        new ArrayList<String>();
        list.add("code");
        list.add("code");
        list.add("quiz");
        list.add("code");
    
        // count the frequency of the word "code"
        System.out.println("The frequency of the word code is: "+ 
                                Collections.frequency(list, "code")); 
    }
}

// Java program to demonstrate working of 
// Collections.frequency()
// for custom defined objects
import java.util.*;

public class GFG
{
    public static void main(String[] args)
    {
        // Let us create a list of Student type
        ArrayList<Student> list =
                        new ArrayList<Student>();
        list.add(new Student("Ram", 19));
        list.add(new Student("Ashok", 20));
        list.add(new Student("Ram", 19));
        list.add(new Student("Ashok", 19));
       
        // count the frequency of the word "code"
        System.out.println("The frequency of the Student Ram, 19 is: "+ 
                                Collections.frequency(list, new Student("Ram", 19))); 
    }
}
class Student
{
    private String name;
    private int age;
    
    Student(String name, int age)
    {
    this.name=name;
    this.age=age;
    }
    
    public String getName()
    {
        return name;
    }
    
    public void setName(String name)
    {
        this.name = name;
    }

    public int getAge() 
    {
        return age;
    }
    
    public void setAge(int age)
    {
        this.age = age;
    }
    
    @Override
    public boolean equals(Object o)
    {
        Student s;
        if(!(o instanceof Student))
        {
            return false;
        }
        
        else
        {
            s=(Student)o;
            if(this.name.equals(s.getName()) && this.age== s.getAge())
            {
                return true;
            }
        }
        return false;
    }
}