How many ashaabul kahf were there in surah al kahf?

The Companions of the Cave (Ashab-al-Kahf) are mentioned in Sura Kahf (Qur'an 18:9-26) however the precise number of companions is not stated. The story is narrated to the Messenger (saw) not to become despondent over the failure of his people to understand and accept his call to them to correct their collective way of life. The story is mentioned to emphasis how these sincere and god conscious youth withdrew to the cave from their nation who had refused to serve Allah, fully confident that Allah would support them and not abandon them. The Qur'an goes on to say people started speculating over how many people were in the cave. This is presumably a reference to Christian tradition that claims they comprised Seven Sleepers hiding in a cave outside the city of Ephesus around 250 AD to escape religious persecution, emerging around 300 years later. One of the early versions is narrated by a Syrian bishop Jacob of Serugh (c. 450-521) derived from an earlier Greek source. The Qur'an advises the Messenger: They will say there were three, the fourth of them being their dog; and they will say there were five, the sixth of them being their dog - guessing at the unseen; and they will say there were seven, and the eighth of them was their dog. Say, [O Muhammad], "My Lord is most knowing of their number. None knows them except a few. So do not argue about them except with an obvious argument and do not inquire about them among [the speculators] from anyone." (Qur'an 18:22) So in a nutshell, noone knows their number and it is not necessary to know it. The core Message requires us to understand our purpose in life is to please and serve Allah and to collectively implement and live by this understanding as nations. And keep yourself patient [by being] with those who call upon their Lord in the morning and the evening, seeking His countenance. And let not your eyes pass beyond them, desiring adornments of the worldly life, and do not obey one whose heart We have made heedless of Our remembrance and who follows his desire and whose affair is ever [in] neglect. And say, "The truth is from your Lord, so whoever wills - let him believe; and whoever wills - let him disbelieve." Indeed, We have prepared for the wrongdoers a fire whose walls will surround them. And if they call for relief, they will be relieved with water like murky oil, which scalds [their] faces. Wretched is the drink, and evil is the resting place. (Qur'an 18:28-29)