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How do I check if a type provides a parameterless constructor?
...Type.EmptyTypes, null);
There's a caveat for value types, which aren't allowed to have a default constructor. You can check if you have a value type using the Type.IsValueType property, and create instances using Activator.CreateInstance(Type);
...
What's the best way of implementing a thread-safe Dictionary?
...
As Peter said, you can encapsulate all of the thread safety inside the class. You will need to be careful with any events you expose or add, making sure that they get invoked outside of any locks.
public class SafeDictionary<TKey, TValue>: IDictionary&...
Why is using “for…in” for array iteration a bad idea?
...undefined
undefined
undefined
5
*/
can sometimes be totally different from the other:
var a = [];
a[5] = 5;
for (var x in a) {
// Shows only the explicitly set index of "5", and ignores 0-4
console.log(x);
}
/* Will display:
5
*/
Also consider tha...
When should I use a NoSQL database instead of a relational database? Is it okay to use both on the s
...proven and suitable for 99% of the real world applications. You can practically do anything with relational databases.
But, there are limitations on speed and scaling when it comes to massive high availability data stores. For example, Google and Amazon have terabytes of data stored in big data cen...
How to deal with “java.lang.OutOfMemoryError: Java heap space” error?
...form you are running on. In Windows 32 bit this is around 2GB (not specifically heap but total amount of memory per process). It just happens that Java chooses to make the default smaller (presumably so that the programmer can't create programs that have runaway memory allocation without running int...
Apache Tomcat Not Showing in Eclipse Server Runtime Environments
I have tomcat 5.5 installed, running and verifiable at http://localhost:8080/ . The Tomcat menu option appears in the Eclipse menu bar and I can start and stop Tomcat from there. In Eclipse, it does not show as a Server Runtime Environment in Window - Preferences - Server - Runtime Environments, no...
grep, but only certain file extensions
... some scripts to grep certain directories, but these directories contain all sorts of file types.
11 Answers
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Why is volatile needed in C?
...olatile variable.
There are at least three common reasons to use it, all involving situations where the value of the variable can change without action from the visible code: When you interface with hardware that changes the value itself; when there's another thread running that also uses the ...
Array.Copy vs Buffer.BlockCopy
...uffer from one or more severe technical flaws, including not moving memory allocations out of the test loops (which introduces severe GC artifacts), not testing variable vs. deterministic execution flows, JIT warmup, and not tracking intra-test variability. In addition, most answers did not test the...
What is the correct XPath for choosing attributes that contain “foo”?
Given this XML, what XPath returns all elements whose prop attribute contains Foo (the first three nodes):
9 Answers
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