ViewPagerAdapter.java

package com.example.weatherapp.Adapter;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;

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

public class ViewPagerAdapter extends FragmentPagerAdapter {

    private final List<Fragment> fragmentList = new ArrayList<>();
    private final List<String> fragmentTitle = new ArrayList<>();

    public ViewPagerAdapter (FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem (int i) {
        return  fragmentList.get(i);
    }

    @Override
    public int getCount () {
        return fragmentList.size();
    }

    public void addFragment (Fragment fragment, String title) {
        fragmentList.add(fragment);
        fragmentTitle.add(title);
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return fragmentTitle.get(position);
    }

}