goto

问题 Which of the following best translates the English statement "If it's rainy, we will watch a movie. Otherwise we will go to the park." a. if (rainy = true) { gotoAndStop ("movie"); } b. if (rainy == true) { gotoAndStop ("movie"); } c. if (rainy = true) { gotoAndStop ("movie"); } else { gotoAndStop ("park"); } d. if (rainy == true) { gotoAndStop ("movie"); } else { gotoAndStop ("park"); } My answer would be "d" - is that correct? 回答1: Yes, 'd' is the correct answer. The difference between =

问题 I want to know whether it is possible to expose goto label within a function to symbol table from C/C++ For instance, I want to make ret label of the following snippet appeared from the symbol table and can be referred using standard APIs such as dlsym(). Thanks for your help in advance! #include <stdio.h> int main () { void *ret_p = &&ret; printf("ret: %p\n", ret_p); goto *ret_p; return 1; ret: return 0; } 回答1: Thanks to Marc Glisse's comment which is about using inline asm that specifies

问题 Background: This is a follow-up question to this thread about handling EINTR for system calls in C++ (Linux/GCC). Regardless of whether or not I intend to profile my application, it seems like I should be handling system calls setting errno to EINTR as a special case. There are many, many, many opinions about the use of goto . My question: is a system call setting errno to EINTR a case where goto is considered nominal? If not, then how would you suggest converting the following code to handle

问题 I am trying to make a batch text-based game. But i encountered a problem just starting to write it what I have never encountered before. :menu :: the game menu - opens when the game starts cls echo This game is still being made -- expermintal echo Start Screen: echo [1] View Changes echo [2] Start Game echo enter your choice: set /p startchoice = if %startchoice%==1 goto changes if %startchoice%==2 goto startgame When i type in either 1 or 2, it shows the error "goto was unexpected at this

问题 This code is designed to resemble a simpler version of the Pokemon battle gameplay. I've only coded in the attacks. I've been testing thoroughly, and found that an error message (Goto was unexpected at this time) whenever the user confirmed their attack. WARNING!! Code is 96 lines long. At the end, I'll put the problem section, so you can skip this first huge chunk. @echo off Set H1=20 Set A1=8 Set D1=6 Set S1=5 Set H2=14 Set A2=5 Set D2=4 Set S2=8 :Begin CLS Echo Bulbasur Echo %H2%/14 /\

问题 I've posted a code snippet on another forum asking for help and people pointed out to me that using GoTo statements is very bad programming practice. I'm wondering: why is it bad? What alternatives to GoTo are there to use in VB.NET that would be considered generally more of a better practice? Consider this snippet below where the user has to input their date of birth. If the month/date/year are invalid or unrealistic, I'd like to loop back and ask the user again. (I'm using if statements to

问题 I am reading C Programming - A Modern Approach by K.N.King to learn the C programming language and it was noted that goto statements must not skip variable-length array declarations. But now the question is: Why are goto jumps allowed to skip fixed-length array declarations and ordinary declarations? And more precisely, what is the behavior of examples like these, according to the C99 standard? When I tested these cases it seemed like the declarations were actually not jumped over, but is

问题 C++14 has rules for what you can and can't do in a constexpr function. Some of them (no asm , no static variables) seem pretty reasonable. But the Standard also disallows goto in constexpr functions, even while it allows other control flow mechanisms. What's the reasoning behind this distinction? I thought we were past " goto is hard for compilers ". 回答1: My understanding is there was a desire to get relaxed constexpr semantics in C++14. A lot of the restrictions that were relaxed were

问题 What is the best way to manage resources for a C program. Should I use a nested if structure or should I use goto statements? I am aware there is a lot of taboo about goto statements. However, I think it is justified for local resource clean up. I have supplied two samples. One compares a nested if structure and another uses goto statements. I personally find the goto statements make the code easier to read. For those who might argue that the nested if prompt better structure, imagine if the

问题 I have a bit unusual situation - I want to use goto statement to jump into the loop, not to jump out from it. There are strong reasons to do so - this code must be part of some function which makes some calculations after the first call, returns with request for new data and needs one more call to continue. Function pointers (obvious solution) can't be used because we need interoperability with code which does not support function pointers. I want to know whether code below is safe, i.e. it