How to check if a string is a legal “dd/mm/yyyy” date?

Question

Given a string str, how could I check if it is in the dd/mm/yyyy format and contains a legal date ?

Some examples:

bla bla          


        

Answer 1

for dd/mm/yyyy format only

^(0?[1-9]|[12][0-9]|3[01])[\/](0?[1-9]|1[012])[\/]\d{4}$