what's the difference in use between Had better /Had rather ? Thanks before

Question

what's the difference in use between Had better /Had rather ?  Thanks before

Answer

1- Had better: 
We use had better to say what is the best thing to do in a particular situation. 
'You're ill. You had better see a doctor, NOT You have better see a doctor.' 
'I'd better tidy this room up.' 
'Had better' is stronger than 'should' or 'ought to ', although it is not as strong as 'must'. 
I'd better tidy up means that I am going to tidy up, because it is the best thing to do. 
The negative is 'had better not.' 
'Come on. We'd better not waste any time.' 

2- Would rather (NOT had rather): 
Would rather means 'prefer' or 'would prefer' (we use it to express preference) 
'I'd rather walk than hang around for a bus.' 
'Would you rather eat now or later?' 
The negative is 'would rather not.' 
'I'd rather not take any risks.'

Answer

Had better...
Would rather....
No such phrase as "had rather"