PHP - Interfaces vs. Abstract Classes

Interface are similar to abstract classes. The difference between interfaces and abstract classes are: 1. Interfaces cannot have properties, while abstract classes can 2. All interface methods must be public, while abstract class methods is public or protected 3. All methods in an interface are abstract, so they cannot be implemented in code and the abstract keyword is not necessary 4. Classes can implement an interface while inheriting from another class at the same time

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