Great example of Irony would be if I said I would never get hit by car then next hour I get hit by car.

Coincidence would be if I went out for night out with my mates and during that night out I meet a friend that I haven't seen for years.

coincidence-
is more of 2 seperate paths unfolding to cross at an unlikely point.

Like If I Ran out of gas and had to walk to a gas station. And a friend of mine Fell out of a plane that exploded and we met. "Hey!, what a coincidence"

Irony-
More like a fitting contradiction based on actions not usually in control.

"Devils are gonna beat the flyers 4-0 in the series"
and then the devils get sweeped 4-0.
"isnt that ironic"

Many of the examples of irony here are both ironic AND coincidental, suggesting there is some overlap between the two categories. However, it is possible for something to be ironic and yet NOT coincidental.

My favorite example of this is Jafar from Aladdin. Making wishes to be more and more powerful, until he finally wishes to be a genie, in which case he isn't actually powerful at all, but a slave!