Perhaps you didn’t know that you can put multiple conditions on a single case: case mystr when “abc”, “def”, “ghi”, “xyz” .. end But for this specific string-based test, I would use regex: if mystr =~ /\A(?:abc|def|ghi|xyz)\z/ If you don’t want to construct a regex, and you don’t want a case statement, you can create … Read more
Pointer comparisons cannot be signed or unsigned. Pointers are not integers. C language (as well as C++) defines relative pointer comparisons only for pointers that point into the same aggregate (struct or array). The ordering is natural: the pointer that points to an element with smaller index in an array is smaller. The pointer that … Read more
You can consider C++ templates to be an interpreted, functional programming language disguised as a generics system. If this doesn’t scare you, it should 🙂 C# generics are very restricted; you can parameterize a class on a type or types, and use those types in methods. So, to take an example from MSDN, you could … Read more
This code: var_dump(123); var_dump(0123); will get you: int 123 int 83 This is because 0123 is octal notation (because of the 0 at the beginning), while 123 is decimal. For more information, you can take a look at the Integer section of the manual. An even trickier question would have been to ask about 79 … Read more
This is a problem that has already occurred in another arena: competitive games! Here, too, the goal is to assign each player a global “rank” on the basis of a series of 1 vs. 1 comparisons. The difficulty, of course, is that the comparisons are not transitive (I take “subjective” to mean “provided by a … Read more
Javascript objects are excellent for this purpose, since they are essentially key/value stores: // Words to match var words = [“dell”, “ledl”, “abc”, “cba”]; // The output object var anagrams = {}; for (var i in words) { var word = words[i]; // sort the word like you’ve already described var sorted = sortWord(word); // … Read more
To do something when cell is not empty add: if cell.value: which in python is the same as if cell value is not None (i.e.: if not cell.value == None:) Note to avoid checking empty cells you can use worksheet.get_highest_row() and worksheet.get_highest_column() Also I found it useful (although might not be a nice solution) if … Read more
var closestTime = listOfTimes.OrderBy(t => Math.Abs((t – fileCreateTime).Ticks)) .First(); If you don’t want the performance overhead of the OrderBy call then you could use something like the MinBy extension method from MoreLINQ instead: var closestTime = listOfTimes.MinBy(t => Math.Abs((t – fileCreateTime).Ticks)); Something like this: DateTime fileDate, closestDate; ArrayList theDates; long min = long.MaxValue; foreach (DateTime … Read more
From O’Reilly: One marked difference between the System V and POSIX semaphore implementations is that in System V you can control how much the semaphore count can be increased or decreased; whereas in POSIX, the semaphore count is increased and decreased by 1. POSIX semaphores do not allow manipulation of semaphore permissions, whereas System V … Read more
This is what the equals method does: public boolean equals(Object obj) { if (obj instanceof Integer) { return value == ((Integer)obj).intValue(); } return false; } As you can see, there’s no hash code calculation, but there are a few other operations taking place there. Although x.intValue() == y.intValue() might be slightly faster, you’re getting into … Read more