[General] That's what would happen and that's what would have happened.

[arjitsharma]

I heard both sentences use. These have the same meaning. Which one should I use?
1. That's what would happen.
2. That's what would have happened.

 

[bhaisahab]

They do not have the same meaning.

 

[tedmc]

I have heard both sentences used. [STRIKE]These[/STRIKE] They have the same meaning. Which one should I use?
1. That's what would happen.
2. That's what would have happened.

They do not have the same meaning.
1 is about the present - something that is likely to happen given a situation.
2 is about the hypothetical past - something that was likely to happen but didn't.

 

[arjitsharma]

Does "would" work for "does" in the first sentence?
I don't understand it. When should I say?
That's what would happen in real.