switch-statement

Checking for numbers in a switch statement, c++

Is there an easy way to check for digits 0-9 with a switch statement? I'm writing a program to check for certain characters as well as digits. Like checking for '\0', 'F' or 'f', and was wondering if there was also a way to check for 0-9 in a similar fashion. I know I can write a program to return true or false if a character is a dig...

Checking for end of string in a switch statement, c++

I'm writing a program to basically check if a number is a type float, double, or long double for an assignment using switch statements and a state machine. I am stepping through my program, and it gets all the way to the end except doesn't seem to recognize the string terminator '\0'. So I was wondering if that portion of my code is co...

Discrepancy in switch statement results

function skyCoverage( $metarClouds ) { foreach( $metarClouds[0] as $cloudReport ) { $coverageCode = substr( $cloudReport, 0, 3 ); // I check $coverageCode here, and it is indeed "CLR" switch( $coverageCode ) { case "CLR": $cloudCoverage = 0; break;...

PHP switch statement variable scope

In PHP, how is variable scope handled in switch statements? For instance, take this hypothetical example: $someVariable = 0; switch($something) { case 1: $someVariable = 1; break; case 2: $someVariable = 2; break; } echo $someVariable; Would this print 0 or 1/2? ...

Why no switch on pointers?

For instance: #include <stdio.h> void why_cant_we_switch_him(void *ptr) { switch (ptr) { case NULL: printf("NULL!\n"); break; default: printf("%p!\n", ptr); break; } } int main(void) { void *foo = "toast"; why_cant_we_switch_him(foo); return 0; } gcc ...

JavaScript switch with logical operators?

for( count = 1 ; count < 6 ; count++ ) { switch (count) { case (2): document.write("hi"); break; case (count > 3): document.write("bye"); break; case (count >= 4): document.write("lol"); break; } } Because it's not working the way I expect, not printing bye and lol, it makes me think this is invalid in Java...

How to detect a user's language through their IP Address.

I have developed a website www.tenxian.com. It has three language versions, English, Japanese and Chinese. How can I write an effective PHP program which can automatically choose a language version based on the IP address of the visitor? If I use "if-else", the code would be much complicated; If I use switch-case, how to write it sin...

python switch by class name?

I am currently doing this, to do different things based on an object's type: actions = { SomeClass: lambda: obj.name AnotherClass: lambda: self.normalize(obj.identifier) ...[5 more of these]... } for a in actions.keys(): if isinstance(obj, a): return actions[a]() Is it possible ...

why is break required after yield return in a switch statement

Can somebody tell me why compiler thinks that break is necessary after yield return in the following code? foreach (DesignerNode node in nodeProvider.GetNodes(span, node => node.NodeType != NDjango.Interfaces.NodeType.ParsingContext)) { switch (node.ErrorMessage.Severity) { case -1: case 0...

Why the c# compiler requires the break statement in switch construction?

Hi there, I'm having hard time understanding, why the compiler requires using break statement. It's not possible to miss it since the fall through is now allowed. I see the reason for the break in C or C++, but is it needed here. Why it's not a built-in behavior to break after a case is over ? Isn't it just a syntax with no semantic? ...

Switch/case without break inside DllMain

I have a Dllmain that allocates Thread local storage when a thread attaches to this DLL. Code as below: BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) { LPVOID lpvData; BOOL fIgnore; switch (ul_reason_for_call) { case DLL_PROCESS_A...

does a switch idiom make sense in this case?

I'm writing a parser/handler for a network protocol; the protocol is predefined and I am writing an adapter, in python. In the process of decoding the incoming messages, I've been considering using the idiom I've seen suggested elsewhere for "switch" in python: use a hash table whose keys are the field you want to match on (a string in ...

C++ Long switch statement or look up with a map?

In my C++ application, I have some values that act as codes to represent other values. To translate the codes, I've been debating between using a switch statement or an stl map. The switch would look something like this: int code; int value; switch(code) { case 1: value = 10; break; case 2: value = 15; break; } The map...

C++ Switch Statement Case Error

I'm programming a simple text-based RPG using a switch statement for a game loop. The program works fine until I attempt to add another case statement, at which point it gives me the following three errors: "jump to case label" (error occurs at the line of the newly added case), and two "crosses initialization of 'ClassName *objectName'"...

can I put the break on the same line

I have a switch statement that has over 300 case statements. case 'hello': { $say = 'some text'; } break; case 'hi': { $say = 'some text'; } break; Why is it that the break is always on a separate line? Is this required? Is there anything syntactically incorrect about me doing this: case 'hello': { $sa...

Is a switch statement the fastest way to implement operator interpretation in Java

Is a switch statement the fastest way to implement operator interpretation in Java public boolean accept(final int op, int x, int val) { switch (op) { case OP_EQUAL: return x == val; case OP_BIGGER: return x > val; case OP_SMALLER: return x < val; default: r...

Why doesn't my continue execute the next when block in Perl 5.10?

When I run this: use feature ':5.10'; $x=1; given ($x) { when(1) { say '1'; $x = 2; continue; } when (2) { say '2'; } } This should print both 1 and 2, but it only prints 1. Am I missing something? EDIT: I have added $x = 2 and it still prints only "1" ...

C# - Which is the best alternative to ‘switch on type’?

1.) http://channel9.msdn.com/forums/TechOff/411739-switch-objectGetType-/?CommentID=411995 2.) http://blogs.msdn.com/jaredpar/archive/2008/05/16/switching-on-types.aspx 3.) Or is there an even better way....? Please reflect both on speed and ease of reading the code. ...

Switch Statement in C#

Does anyone know if it's possible to include a range in a switch statement (and if so, how)? For example: switch (x) { case 1: //do something break; case 2..8: //do something else break; default: break; } The compiler doesn't seem to like this kind of syntax - neither does it like: case <= 8: ...

Is it a good idea to define a variable in a local block for a case of a switch statement?

I have a rather long switch-case statement. Some of the cases are really short and trivial. A few are longer and need some variables that are never used anywhere else, like this: switch (action) { case kSimpleAction: // Do something simple break; case kComplexAction: { int specialVariable = 5; // ...