The basic premise here is false: the size of a try block makes no difference in performance. Performance is affected by actually raising exceptions at runtime, and that’s independent of the size of the try block. However, keeping try blocks small can lead to better programs. You might catch exceptions to recover and proceed, or … Read more
Consider what you are doing. You’re allocating memory. And if for some reason memory allocation cannot work, you assert. Which is more or less exactly what will happen if you just let the std::bad_alloc propagate back to main. In a release build, where assert is a no-op, your program will crash when it tries to … Read more
Exceptions are not conditionals. The conditional version is clearer. That’s natural: this is straightforward flow control, which is what conditionals are designed for, not exceptions. The exception version is primarily used as an optimization when doing these lookups in a loop: for some algorithms it allows eliminating tests from inner loops. It doesn’t have that … Read more
Using String concatenation is translated into StringBuilder operations by the compiler. To see how the compiler is doing I’ll take a sample class, compile it and decompile it with jad to see what’s the generated bytecode. Original class: public void method1() { System.out.println(“The answer is: ” + 42); } public void method2(int value) { System.out.println(“The … Read more
Extending @KooiInc answer, you can avoid manually escaping every special character by using the source property of the RegExp object. Example: var urlRegex= new RegExp(” + /(?:(?:(https?|ftp):)?\/\/)/.source // protocol + /(?:([^:\n\r]+):([^@\n\r]+)@)?/.source // user:pass + /(?:(?:www\.)?([^\/\n\r]+))/.source // domain + /(\/[^?\n\r]+)?/.source // request + /(\?[^#\n\r]*)?/.source // query + /(#?[^\n\r]*)?/.source // anchor ); or if you want to … Read more
There is a discrepancy between the two examples. The first will execute the “do something” at least once every time even if the statement is never true. The second will only “do something” when the statement evaluates to true. I think what you are looking for is a do-while loop. I 100% agree that while … Read more
I’d nearly always prefer the local variable solution. Memory footprint A single local variable costs 4 or 8 bytes. It’s a reference and there’s no recursion, so let’s ignore it. Performance If this is a simple getter, the JVM can memoize it itself, so there’s no difference. If it’s a expensive call which can’t be … Read more
You missed one. First code for correctness, then for clarity (the two are often connected, of course!). Finally, and only if you have real empirical evidence that you actually need to, you can look at optimizing. Premature optimization really is evil. Optimization almost always costs you time, clarity, maintainability. You’d better be sure you’re buying … Read more
It’s not faster. If you really care, compile with assembler output for your platform and look to see. It doesn’t matter. This never matters. Write your infinite loops however you like.
To my knowledge they are identical. I think there maybe a few engines out there that don’t support the numbered syntax but I’m not sure which. I vaguely recall a question on SO a few days ago where explicit notation wouldn’t work in Notepad++. The only time I would use explicitly numbered repetition is when … Read more