Swift: Use of undeclared type

Question

I'm implementing a class but I'm getting this error:

Use of undeclared type 'myProtocol'

Here is my code:

class LocalContactService: myProtocol{

Any of you knows why I'm getting this error?

Solution 1

i had the same error .in my case i found accidentally that i added my swift files into "copy bundle resource" in "build phase" i removed all swift file except assets then everything worked fine.

Solution 2

the issue is caused when the classes in question do not belong to the same targets, usually the test target is missing. Just make sure the following check boxes are ticked. you can refer to original answer: https://stackoverflow.com/a/30737191/3992606

Solution 3

Perhaps you've never defined myProtocol. Or if you have, maybe it's out of scope in the LocalContactService class

Solution 4

I got this error when someone pushed changes that they made to the project.pbxproj file.

Select the file hit delete and choose the option to Remove Reference

Add the file back to the project, clean (cmd + shift + k), and rebuild

Solution 5

I my case I had to clean the build folder, close the project, run pod install, and then the issue disappeared.

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Comments

[K. Biermann]

Have you declared a protocol "myProtocol"? If so, please show us the declaration. If not, I would recommend you to read developer.apple.com/library/ios/documentation/Swift/Conceptu‌​al/…

[user2924482]

How do I define the protocol?

[K. Biermann]

Here are some examples: developer.apple.com/library/ios/documentation/Swift/Conceptu‌​al/… A basic definition (without any useful content) would be protocol myProtocol {}

[rr1g0]

This was exactly my problem! And I had it on the same file, so it wasn't obvious. Thanks

[Subcreation]

I ran into this issue while working through this SwiftUI tutorial: developer.apple.com/tutorials/swiftui/handling-user-input and following the steps you provided fixed it. Thanks!

[ecth]

Thanks, that solved my issue! Every time this is so insanely unexpected. I am hopping between kotlin and swift all the time and I don't expect such errors from not marking the unit tests. Imo very unintuitive.