#1. We need to know design patterns to find solutions for frequently occurring problems. And we want to reuse these solutions whenever we face a similar situation in the future.
#2. These are one kind of template to address solutions in many different situations.
#3. In other words, these are the descriptions of how different objects and their respective classes solve a design problem in a specific context.
#4. Here we have discussed 23 design patterns as outlined by the Gang of Four. These patterns can be classified into three major categories:
These patterns mainly deal with the instantiation process. Here we make the systems independent from how their objects are created, collected, or represented. The following ...