Showing results for Code - The Old New Thing

Today's Little Program is an exercise that solves the following problem: Given a JavaScript array and an unsorted array (possibly containing duplicates), calculate the result of deleting all of the elements from the original array as specified by the indices. For example, suppose and . The indices specify that elements 2 (charles), 4 (eve...

C# has operators and to control the behavior of the language in the face of integer overflow. There are also and statements which apply the behavior to blocks of statements rather than single expressions. Why, then, doesn't this code below raise an overflow exception? (Mini-exercise: Why couldn't I have just written ?) The answer is th...

In the C# language, operation/assignment such as are explicitly not atomic. But you already knew this, at least for properties. Recall that properties are syntactic sugar for method calls. A property declaration is internally converted to the equivalent of Accessing a property is similarly transformed. Note that the only operations you c...

A customer was having trouble manipulating the console from a C# program: We found that C# can read only ASCII data from the console. If we try to read non-ASCII data, we get garbage. Observe that this program is unable to read the Å and ö characters. They come back as garbage. Although there are three code pages that have spec...

Often, we receive problem reports from customers who failed to keep their eye on the code page. Does the function support files with non-ASCII characters in their names? We find that the function either fails outright or returns question marks when asked to provide information for files with non-ASCII characters in their name. If we ask for...

Welcome to CLR Week 2014. Don't worry, it'll be over in a few days. A customer wanted to know why their was displaying the infamous Current thread must be set to single thread apartment (STA) mode before OLE calls can be made error. "Even though we set the to , the apartment state is still . Curiously, if we put the above code in a standalo...

A customer found that under heavy load, their application would occasionally hang. Debugging the hang shows that everybody was waiting for the critical section. The catch was that the critical section was reported as locked, but the owner thread did not exist. How can a critical section be owned by thread that no longer exists? There are two...

Clean-up functions can't fail, so what do you do if you encounter a failure in your clean-up function? You have to keep cleaning up. Some people like to follow this pattern for error checking: And some like to put it inside a cute flow control macro like or even Whatever floats your boat. But you have to be careful if using this p...

When Explorer copies files around, it doesn't really know what the maximum file size supported by any file system happens to be. (That information is not reported by .) So it guesses. If the file system name is or , then Explorer assumes that the maximum file size is 4GB − 1. Also, if a file operation fails with the error , and Explorer ca...

Suppose you have a bunch of people, and you want to break them up into m teams of size n. (Therefore you have a total of nm people.) Today's Little Program will enumerate the ways this can be done. Formally, let's say that you have a collection of size nm, and you want to enumerate the ways of partitioning the collection into m subsets, each sub...