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Why historically do people use 255 not 256 for database field magnitudes?
You often see database fields set to have a magnitude of 255 characters, what is the traditional / historic reason why? I assume it's something to do with paging / memory limits, and performance but the distinction between 255 and 256 has always confused me.
...
Why is “while ( !feof (file) )” always wrong?
...e is again std::cin, just as before.
POSIX, write(2) to flush a buffer:
char const * p = buf;
ssize_t n = bufsize;
for (ssize_t k = bufsize; (k = write(fd, p, n)) > 0; p += k, n -= k) {}
if (n != 0) { /* error, failed to write complete buffer */ }
The result we use here is k, the numb...
How to handle Objective-C protocols that contain properties?
...hInteger:(factor*amount)];
}
// <<
@end
int main(int argc, const char * argv[])
{
@autoreleasepool {
Person *duncan=[[Person alloc]initConforming];
duncan.firstname=@"Duncan";
duncan.lastname=@"Smith";
[Viewer printLargeDescription:duncan];
S...
Best way to parseDouble with comma as decimal separator?
... The problem with NumberFormat is that it will silently ignore invalid characters. So if you try to parse "1,23abc" it will happily return 1.23 without indicating to you that the passed-in String contained non-parsable characters. In some situations that might actually be desirable, but I don't ...
Regular expression to match URLs in Java
...ckzah|xxx)"
+ "|y[et]"
+ "|z[amw]))";
/**
* Good characters for Internationalized Resource Identifiers (IRI).
* This comprises most common used Unicode characters allowed in IRI
* as detailed in RFC 3987.
* Specifically, those two byte Unicode characters are ...
How many and which are the uses of “const” in C++?
...p you to decide when and when not you need to copy.
struct MyString {
char * getData() { /* copy: caller might write */ return mData; }
char const* getData() const { return mData; }
};
Explanation: You might want to share data when you copy something as long as the data of the originally ...
Error “initializer element is not constant” when trying to initialize variable with const
...s_pFooInit = (&(const foo_t){ .a=2, .b=4, .c=6 });
int main (int argc, char **argv) {
const foo_t *const f1 = &s_FooInit;
const foo_t *const f2 = s_pFooInit;
printf("Foo1 = %d, %d, %d\n", f1->a, f1->b, f1->c);
printf("Foo2 = %d, %d, %d\n", f2->a, f2->b, f2->...
Should I impose a maximum length on passwords?
...elves), but my bank has a requirement that passwords are between 6 and 8 characters long, and I started wondering...
20 A...
How do I check that a Java String is not all whitespaces?
I want to check that Java String or character array is not just made up of whitespaces, using Java?
15 Answers
...
LINQ equivalent of foreach for IEnumerable
...d evaluating Funcs
var evaluatedObservable = observable.ToEnumerable().Select(func => func()).ToList();
//Win
Assert.That(evaluatedObservable,
Is.EquivalentTo(values.ToList()));
}
The following fails with the error:
Expected: equivalent to < 0, 1, 2, 3, 4, 5, 6, 7, 8, ...