What Is Interface In Php?

1.	What Is Interface In Php?
Answer» Interfaces are defined USING the interface keyword. All methods declared in an interface MUST be public. Classes defined as Interface may not be instantiated(create object). To EXTEND the interface class, IMPLEMENTS OPERATOR is used. You can inherit number of interface class at the time of extending and number of abstract class separated by comma. All methods in the interface must be implemented within a child class; failure to do so will result in a fatal error. Interfaces can be extended like classes using the extends operator. The class implementing the interface must use the exact same method signatures as are defined in the interface. Not doing so will result in a fatal error. Type hint & number of parameter must be match.

Answer»

Interfaces are defined USING the interface keyword.
All methods declared in an interface MUST be public. Classes defined as Interface may not be instantiated(create object).
To EXTEND the interface class, IMPLEMENTS OPERATOR is used.
You can inherit number of interface class at the time of extending and number of abstract class separated by comma.
All methods in the interface must be implemented within a child class; failure to do so will result in a fatal error.
Interfaces can be extended like classes using the extends operator.
The class implementing the interface must use the exact same method signatures as are defined in the interface. Not doing so will result in a fatal error.
Type hint & number of parameter must be match.

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