syntax

问题 My question was triggered by this discussion on SO, which did not lead to an answer that would really explain the issue. I am "rewriting" it here in a slightly different way, because I want to make it more clear what the real problem is and therefore hope to get an answer here. Consider the following two Ruby expressions: 1 * a - 3 1 && a = 3 From the Ruby precedence table, we know that of the operators mentioned here, * has the highest precedence, followed by - , then by && and finally by =

问题 My question was triggered by this discussion on SO, which did not lead to an answer that would really explain the issue. I am "rewriting" it here in a slightly different way, because I want to make it more clear what the real problem is and therefore hope to get an answer here. Consider the following two Ruby expressions: 1 * a - 3 1 && a = 3 From the Ruby precedence table, we know that of the operators mentioned here, * has the highest precedence, followed by - , then by && and finally by =

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 2 years ago . Improve this question How arguments list should be read ? What the syntax in arguments list - the one like object definition but with equality signs? Media.configureVideo = function (session, uploadId, caption, durationms, delay, { audio_muted = false, trim_type = 0, source_type = 'camera', // ...

问题 We are currently in the /home/student/ directory. We execute the following commands: pwd; (ls) || { cd .. && ls student/; } && cd student || cd / && cd ; The commands that are executed are: pwd, ls, cd student, cd /, cd Here is what I think: pwd is executed, because it's the first command (ls) is executed in a subshell, because the commands are seperated with ";" the code on the right of || isn't executed, since the code on the left of || was executed So far everything clear, I guess. But I

问题 We are currently in the /home/student/ directory. We execute the following commands: pwd; (ls) || { cd .. && ls student/; } && cd student || cd / && cd ; The commands that are executed are: pwd, ls, cd student, cd /, cd Here is what I think: pwd is executed, because it's the first command (ls) is executed in a subshell, because the commands are seperated with ";" the code on the right of || isn't executed, since the code on the left of || was executed So far everything clear, I guess. But I

问题 What does the question mark in Erlang syntax mean? For example: Json = ?record_to_json(artist, Artist). The full context of the source can be found here. 回答1: Erlang uses question mark to identify macros. For e.g. consider the below code: -ifdef(debug). -define(DEBUG(Format, Args), io:format(Format, Args)). -else. -define(DEBUG(Format, Args), void). -endif. As the documentation says, Macros are expanded during compilation. A simple macro ?Const will be replaced with Replacement . This snippet

问题 I have checked out some code and I got an error ('invalid expression term "^"' to be exact) in the line // choices is a regular array return choices[^1]; I have never seen a unary caret operator (I am only aware of the XOR operator, but that one obviously takes two operands). Does this operator exist and if so, what does it do? Note: The site https://www.tutorialsteacher.com/csharp/csharp-operators mentions a unary caret operator in the precedence table but it does not explain what it does.

问题 Is there a good way in C# to mimic the following python syntax: mydict = {} mydict["bc"] = {} mydict["bc"]["de"] = "123"; # <-- This line mydict["te"] = "5"; # <-- While also allowing this line In other words, I'd like something with [] style access that can return either another dictionary or a string type, depending on how it has been set. I've been trying to work this out with a custom class but can't seem to succeed. Any ideas? Thanks! Edit: I'm being evil, I know. Jared Par's solution is

问题 Is there a good way in C# to mimic the following python syntax: mydict = {} mydict["bc"] = {} mydict["bc"]["de"] = "123"; # <-- This line mydict["te"] = "5"; # <-- While also allowing this line In other words, I'd like something with [] style access that can return either another dictionary or a string type, depending on how it has been set. I've been trying to work this out with a custom class but can't seem to succeed. Any ideas? Thanks! Edit: I'm being evil, I know. Jared Par's solution is

问题 I've just spent the last day debugging something in which I ultimately ended up on an offending line. The path to this line wasn't exactly clear, and there was a slo-mo face palm once I spotted it... int v = func(&v); // why am I allowed to do this. Should this not generate some sort of 'var used before defined' warning? It was incredibly annoying because there was no compiler error or warning? and of course, no red suiggly line under the syntax :(. So I skipped right over it... oddly, it