Also good to know these patterns if you're dealing with a lot of legacy code, particularly 199x - 201x code that implemented a lot of these patterns.
Some of them are straightforward (factory, adapter). Some of them are almost never used (flyweight). Some are more particular to a programming language; you might see a lot of visitor patterns in C++ code, for instance, but IIRC, that wouldn't come up in Smalltalk because it supported paradigms like double dispatch out of the box.
Some of them are straightforward (factory, adapter). Some of them are almost never used (flyweight). Some are more particular to a programming language; you might see a lot of visitor patterns in C++ code, for instance, but IIRC, that wouldn't come up in Smalltalk because it supported paradigms like double dispatch out of the box.