Relationship between gethashcode equals and dictionary, hash, and list

Dictionary, hashset, and list can all see functions such as contains.

For example, dictionary. the containskey (keytest) function first calls keytest. gethashcode compares whether such a hashcode already exists. If yes, true is returned directly. If no, it cannot be determined that such a key does not exist, because hashcode may conflict with each other. (If hash is equivalent, the objects must be equal. If they are not equal, the objects may be unequal ), therefore, use the override method equals to search for the data.

The default equals is referenceequals for objects.

That is to say, if you are lazy, you can not write gethashcode, as long as you write equals, those structures such as dictionary are normal, but the performance is poor. After all, hashcode is faster and faster.