13. When would you use a pointer to a function? Pointers to functions are interesting when you pass them to other functions. A function that takes function pointers says, in …
9. Is NULL always equal to 0(zero)? The answer depends on what you mean by “equal to.” If you mean “compares equal to,” such as if ( /* … */ …
7. Can you subtract pointers from each other? Why would you? If you have two pointers into the same array, you can subtract them. The answer is the number of …
5. What is a void pointer? A void pointer is a C convention for “a raw address.” The compiler has no idea what type of object a voidpointer “really points …
3. What is a null pointer? There are times when it’s necessary to have a pointer that doesn’t point to anything. The macro NULL, defined in <stddef.h>, has a value …
1. What is indirection? If you declare a variable, its name is a direct reference to its value. If you have a pointer to a variable, or any other object …
9. How can you tell whether two strings are the same? The standard C library provides several functions to compare two strings to see whether they are the same. One …
7. How can I convert a number to a string? The standard C library provides several functions for converting numbers of all formats (integers, longs, floats, and so on) to …
5. How can I pad a string to a known length? Padding strings to a fixed length can be handy when you are printing fixed-length data such as tables or …
3. How can I remove the leading spaces from a string? The C language does not provide a standard function that removes leading spaces from a string. It is easy, …
