6. How do I determine whether a character is numeric, alphabetic, and so on? The header file ctype.h defines various functions for determining what class a character belongs to. These …
4. What is the difference between a free-standing and a hosted environment? Not all C programmers write database management systems and word processors. Some write code for embedded systems, such …
3. How can I write functions that take a variable number of arguments? Use <stdarg.h>. This defines some macros that let your program deal with variable numbers of arguments. There’s …
1. Why should I use standard library functions instead of writing my own? The standard library functions have three advantages: they work, they’re efficient, and they’re portable. They work: Your …
25. How does free() know how much memory to release? There’s no standard way. It can vary from compiler to compiler, even from version to version of the same compiler. …
23. What is a “null pointer assignment” error? What are bus errors, memory faults, and core dumps? These are all serious errors, symptoms of a wild pointer or subscript. Null …
21. What happens if you free a pointer twice? If you free a pointer, use it to allocate memory again, and free it again, of course it’s safe If you …
19. What is the stack? A “stack trace” is a list of which functions have been called, based on this information. When you start using a debugger, one of the …
17. What is the difference between far and near ? Compilers for PC compatibles use two types of pointers. near pointers are 16 bits long and can address a 64KB …
15. Is it better to use malloc() or calloc()? Both the malloc() and the calloc() functions are used to allocate dynamic memory. Each operates slightly different from the other. malloc() …
