Teach yourself C in 24 hours Book

Pedagogically flawed and programming faults abound. Here is an incomplete list of gripes:

- The return type Zhang specifies for main() is wildly inconsistent. Sometimes it's void, sometimes it's int, sometimes it's discarded all together. On top of that, it can even be internally inconsistent: the return type will be set to void and then a 0 is returned at the end of main(). There is no excuse for this as the C standards are clear that main()'s return type is int, and the return value is 0 upon successful execution.
- Zhang doesn't explain why the value returned by getchar() is stored in an int variable instead of a char variable. I think this stands in need of explanation. (By contrast, Kernighan & Ritchie (K&R) are sure to point out that the EOF constant is not itself a char, actually providing an understanding of the practice.)
- No mention that the evaluation order of function calls is undefined in C. That is, if you write an expression like foo(writingfunction(a), readingfunction(a)) it is not guaranteed that the write takes place before the read. If you are unaware of this fact, it is going to screw you up good sooner or later.
- Doesn't explain that an assignment is an expression (and logically also provides no examples that exploit this fact).
- Doesn't mention that type declarations should be at the top of a function.
- The basic if-statement is introduced in Hour 10 (!), while the for- and while-loops have been introduced before that. Weird.
- The example Zhang provides in order to illustrate the functionality of the do-while loop doesn't clarify why it is a welcome alternative to the regular while-loop. To the beginning programmer this is probably confusing. It's really not that hard to come up with an example that demonstrates its circumstantial virtues.
- The examples in general are extremely tedious and uninspired. They pretty much always consist solely of function calls and result prints. Context is missing.
- Zhang only mentions labels in the context of goto statements. He fails to mention that the break and continue statements can also be used in combination with labels.
- strcpy() is treated, but strncpy() goes unmentioned while it is generally the recommended alternative.
- Zhang doesn't check the return value of a function like strcpy(). It is characteristic of C that error-checking and error-handling belong to the user's responsibilities. Zhang sets a bad example in this regard.