The C and C++ standards do not support this feature. However, the GNU Compiler Collection (GCC) includes a non-standard extension for doing this, as described in the Labels as Values section of the Using the GNU Compiler Collection manual. Essentially, they have added a special unary operator && that reports the address of the label … Read more
James Gosling created the original JVM with support of goto statements, but then he removed this feature as needless. The main reason goto is unnecessary is that usually it can be replaced with more readable statements (like break/continue) or by extracting a piece of code into a method. Source: James Gosling, Q&A session
The only way of doing this in MSVC is by using inline assembly (which basically buggers you for x64): int _tmain(int argc, _TCHAR* argv[]) { case_1: void* p; __asm{ mov [p],offset case_1 } printf(“0x%p\n”,p); return 0; } If you plan on doing something like this, then the best way would be to write the whole … Read more
As already pointed out by all the answers goto – a reserved word in Java and is not used in the language. restart: is called an identifier followed by a colon. Here are a few things you need to take care of if you wish to achieve similar behavior – outer: // Should be placed … Read more
You’ve got two problems. One problem is that a goto breaks a for-loop. The other, labels are quite difficult in parenthesis. The goto breaks always and all nested loops, even if the label of the goto is in the same block, and the for-variables are lost immediately after the jump. In parenthesis lables are “two … Read more
They are equivalent, even if you turn the optimizer off. Example: #include <stdio.h> extern void f(void) { while(1) { putchar(‘ ‘); } } extern void g(void) { for(;;){ putchar(‘ ‘); } } extern void h(void) { z: putchar(‘ ‘); goto z; } Compile with gcc -O0 gives equivalent assembly for all 3 functions: f: ; … Read more
I am not sure what do you mean by clean up code but in C++ there is a concept called “resource acquisition is initialization” and it should be the responsibility of your destructors to clean up stuff. (Note that in C# and Java, this is usually solved by try/finally) For more info check out this … Read more
You can ask gcc to warn you when you jump over a variable definition by using -Wjump-misses-init and then you can use -Werror (or, more precisely, -Werror=jump-misses-init) to force the users to deal with it. This warning is included in -Wc++-compat so the gcc developers are aware that the code behaves differently in C versus … Read more
Unless you are programming in assembler, GOTO should always be treated the same way as the life vest of the airplanes: it is good to have them available, but if you need to use them it means that you are in big trouble.
Caution: fflush(stdin); may be undefined behavior. Read: Why fflush(stdin) is wrong? int fflush(FILE *ostream); The ostream points to an output stream or an update stream in which the most recent operation was not input, the fflush function causes any unwritten data for that stream to be delivered to the host environment to be written to … Read more