In swift 3 and above

=== (or !==)

• Checks if the values are identical (both point to the same memory address).
• Comparing reference types.
• Like == in Obj-C (pointer equality).

== (or !=)

• Checks if the values are the same.
• Comparing value types.
• Like the default isEqual: in Obj-C behavior.

Here I compare three instances (class is a reference type)

https://stackoverflow.com/questions/24002819/difference-between-and

Difference between == and ===

原文：https://www.cnblogs.com/feng9exe/p/9104135.html