Suppose I was trying to create a mask in C for bitwise operations, like What does the x mean? I see a lot of numbers written with that 0x format and I don’t understand why and have been unable to find an explanation that really makes sense to me, maybe I’m not searching the right … Read more
What’s wrong with using one of the following?
If you want to practice advanced features of C, how about pointers? We can toss in macros and xor-swap for fun too! A pointer (e.g. char *, read from right-to-left as a pointer to a char) is a data type in C that is used to refer to location in memory of another value. In this case, the location where … Read more
none shows up twice in this code snippet: And then: If, for example, you later had: or or something to that effect, we would say none is “used”, but as the code is, you have: “none” set but not used; exactly what the compiler said. In the pastebin link I see your problem: You wrote this: You meant to write this: … Read more
In C, “strings” are just plain char arrays. Therefore, you can’t directly concatenate them with other “strings”. You can use the strcat function, which appends the string pointed to by src to the end of the string pointed to by dest: Here is an example from cplusplus.com: For the first parameter, you need to provide the destination buffer itself. The destination buffer must … Read more
I may guess, the old instance of your program is still running. Windows does not allow to change the files which are currently “in use” and your linker cannot write the new .exe on the top of the running one. Try stopping/killing your program.
You can only have one flexible array member in a struct, and it must always be the last member of the struct. In other words, in this case you’ve gone wrong before you call malloc, to the point that there’s really no way to call malloc correctly for this struct. To do what you seem to want (arrays … Read more
Answer: sizeof returns the size of the type in bytes. Example: sizeof(char) is 100% guaranteed to be 1, but this does not mean, that it’s one octet (8 bits). Proved by the standard: in 6.5.3.4, point 2: The sizeof operator yields the size (in bytes) of its operand, which may be an expression or the parenthesized name of a type. The … Read more
declares ptr a pointer to const int type. You can modify ptr itself but the object pointed to by ptr shall not be modified. While declares ptr a const pointer to int type. You are not allowed to modify ptr but the object pointed to by ptr can be modified. Generally I would prefer the declaration like this which make it easy to read and understand (read from right to left):