2016年2月5日 · #define is a preprocessor instruction that defines a macro. In your case macro dItemName with value L"CellPhone". Macros are bad mostly because they are processed before the actual code is. This means that they aren't subjected to scopes and to the rules of C++ syntax.

2011年12月29日 · In the case of your code, that is not the case since you have an internal definition inside a non-procedural define. You could fix it by making `bootstrap-c-code' bind to a procedure.

2015年11月11日 · I just discovered Racket a few days ago, and I'm trying to get more comfortable with it by writing a little script that generates images to represent source code using #lang slideshow. I know that...

2013年10月27日 · What are the advantages and disadvantages of using #define over const (and vice versa)? When I read about bad programming practices specifically magic numbers, I found myself using #define more frequently. Some questions popped into my mind such as: Is it bad to use #define a lot? Does it take memory space? Would it be faster to use const instead?

2013年10月11日 · The problem is that, when you define an internal procedure inside the body of a lambda, you have to write an expression after the definition, typically calling the internal procedure.

Question #1: Is declaring a variable inside a loop a good practice or bad practice? I've read the other threads about whether or not there is a performance issue (most said no), and that you should always declare variables as close to where they are going to be used.

2014年10月22日 · bad-if, on the other hand, is a standard procedure. In that case, Scheme first evaluates both expressions since they are parameters to the procedure bad-if before actually executing bad-if. So, even for x = 0, (* x (factorial -1)) will be evaluated, which will in turn evaluate (* x (factorial -2)) and so on, in an endless loop.

2009年10月28日 · Is it better to use static const variables than #define preprocessor? Or does it maybe depend on the context? What are advantages/disadvantages for each method?

No, I did not state this. Because that's what macros are used for. Note that C very well has constants! 1 is a constant of type int, 0.3f is a float constant, etc. The problem you have are symbolic constants with a user-defined type. Use macros for them. Different translation phase, but that's how it works in C. If you are in rome behave like a roman.

2018年10月10日 · Is this true? Is it bad practice in C++ to use const variables instead of #define when specifying array sizes? If so, why? In C, apparently you're stuck with #define: you don't have any other choice. But in C++ you clearly have at least two choices, so is one better than the other? Is there a risk to using one over the other?