Interfaces

[chacha102]

This may be a really stupid question that I just haven't figured out yet/ (I've only done php for 1-2 years). What are the benefits of using an interface on a class? I realize that you can make sure that certain methods are used, but is that all? Is there some great functionality that I haven't learned yet?

[obsidian]

This may be a really stupid question that I just haven't figured out yet/ (I've only done php for 1-2 years). What are the benefits of using an interface on a class? I realize that you can make sure that certain methods are used, but is that all? Is there some great functionality that I haven't learned yet?

 

In my personal experience, interfaces have been most practical when I have worked with a team of developers, because it allows me to define a set of rules to be followed and I can dole out the individual classes to be developed by team members knowing they will fit my API because they implement my interface. I very seldom use them personally unless I am trying to follow a specific API for multiple different classes or modules within a larger framework. I'm sure there are other pros to using them, but I will let those more well versed than I point them out

[genericnumber1]

As has been stated, I use them most when implementing an API. A lesser used reason I see for interfaces is they let you have multiple lines of inheritance... though I can't say I've ever used them for that reason.

[DarkWater]

I use them, like most people do, for APIs and making sure everything plays nicely together by following a strict format (that way the actual type of object isn't that important.  They'll all work the same if they have the same public functions as defined by an interface).  I also use them for grouping objects.  I know in Java that it's called the Marker pattern.  I'm pretty sure that it's called the same thing.  It's only useful in PHP5 where we have type hinting though.