C Is Objective-C

One of the most important features of Objective-C is that it is a pure superset of C. You can think of C as a domain-specific language embedded in Objective-C for low-level tasks and a subset of Smalltalk as a domain-specific language embedded in Objective-C for high-level tasks.

There is nothing wrong with solving a problem using pure C. One of the mistakes that a lot of people make when learning Objective-C is to assume that they must stop using C. For a lot of things, the C solution is the correct one.