error:'implicit declaration of function 'nslog' is invalid at C99'

Question

How can I fix this error: 'implicit declaration of function 'nslog' is invalid at C99'. please tell something about this error why this is occuring.

Answer 1

Upper/lower case is important in Objective-C, so the correct use is not nslog but NSLog.

Answer 2

It may be because you haven’t added the foundation framework to your project.

Right click on your top level project folder, click Add -> Exisiting Frameworks and add ‘Foundation Framework’ from the list.