Is a switch statement actually faster than an if statement? I ran the code below on Visual Studio 2010’s x64 C++ compiler with the /Ox flag: #include <stdlib.h> #include <stdio.h> #include <time.h> #define MAX_COUNT (1 << 29) size_t counter = 0; size_t testSwitch() { clock_t start = clock(); size_t i; for (i = 0; i … Read more
I am working on some Java code which needs to be highly optimized as it will run in hot functions that are invoked at many points in my main program logic. Part of this code involves multiplying double variables by 10 raised to arbitrary non-negative int exponents. One fast way (edit: but not the fastest … Read more
Compiling the following code and got the error of type illegal. int main() { // Compilation error – switch expression of type illegal switch(std::string(“raj”)) { case”sda”: } } You cannot use string in either switch or case. Why? Is there any solution that works nicely to support logic similar to switch on strings? 22 Answers … Read more
I wrote a program which involves use of switch statements, however on compilation it shows: Error: Jump to case label. Why does it do that? #include <iostream> int main() { int choice; std::cin >> choice; switch(choice) { case 1: int i=0; break; case 2: // error here } } 4 Answers 4
How would you use a switch case when you need to test for a or b in the same case? switch (pageid) { case “listing-page” || “home-page”: alert(“hello”); break; case “details-page”: alert(“goodbye”); break; } 7 Answers 7
so I want to use a switch statement like this: switch (scrollLeft) { case (<1000): //do stuff break; case (>1000 && <2000): //do stuff break; } Now I know that either of those statements (<1000) or (>1000 && <2000) won’t work (for different reasons, obviously). What I’m asking is the most efficient way to do … Read more
In one of my first code reviews (a while back), I was told that it’s good practice to include a default clause in all switch statements. I recently remembered this advice but can’t remember what the justification was. It sounds fairly odd to me now. Is there a sensible reason for always including a default … Read more
I have a question of using switch case for instanceof object: For example: my problem can be reproduced in Java: if(this instanceof A) doA(); else if(this instanceof B) doB(); else if(this instanceof C) doC(): How would it be implemented using switch…case? 24 Answers 24
The best way I can describe what I’m looking for is to show you the failed code I’ve tried thus far: case car when [‘honda’, ‘acura’].include?(car) # code when ‘toyota’ || ‘lexus’ # code end I’ve got about 4 or 5 different when situations that should be triggered by approximately 50 different possible values of … Read more
First I’ll state that I’m much more familiar with enums in C# and it seems like enums in java is a quite mess. As you can see, I’m trying to use a switch statement @ enums in my next example but I always get an error no matter what I’m doing. The error I receive … Read more
