大约有 48,000 项符合查询结果（耗时：0.0840秒） [XML]
What makes JNI calls slow?
...thods, in 2010 I measured calls at an average 40 ns on my Windows desktop, and 11 ns on my Mac desktop. Unless you're making many calls, you're not going to notice.
That said, calling a native method can be slower than making a normal Java method call. Causes include:
Native methods will not be i...
What's the difference between belongs_to and has_one?
What is the difference between a belongs_to and a has_one ?
5 Answers
5
...
NSLog/printf specifier for NSInteger?
A NSInteger is 32 bits on 32-bit platforms, and 64 bits on 64-bit platforms. Is there a NSLog specifier that always matches the size of NSInteger ?
...
Creating a range of dates in Python
I want to create a list of dates, starting with today, and going back an arbitrary number of days, say, in my example 100 days. Is there a better way to do it than this?
...
JMS Topic vs Queues
I was wondering what is the difference between a JMS Queue and JMS Topic.
9 Answers
9
...
Using StringWriter for XML Serialization
...t prefixed with an upper-case "N", hence an 8-bit encoding, such as UTF-8) and not an NVARCHAR string (prefixed with an upper-case "N", hence the 16-bit UTF-16 LE encoding).
The fix should have been as simple as:
In the first case, when adding the declaration stating encoding="utf-8": simply don'...
Relationship between hashCode and equals method in Java [duplicate]
...ctions where unicity of elements is calculated according to both .equals() and .hashCode(), for instance keys in a HashMap.
As its name implies, it relies on hash tables, and hash buckets are a function of the object's .hashCode().
If you have two objects which are .equals(), but have different ha...
Query for documents where array size is greater than 1
...
2.Create extra field NamesArrayLength, update it with names array length and then use in queries:
db.accommodations.find({"NamesArrayLength": {$gt: 1} });
It will be better solution, and will work much faster (you can create index on it).
...
HTTP authentication logout via PHP
...omes from the HTTP specification (section 15.6):
Existing HTTP clients and user agents typically retain authentication
information indefinitely. HTTP/1.1. does not provide a method for a
server to direct clients to discard these cached credentials.
On the other hand, section 10.4.2 say...
What are “first class” objects?
...r something else said to be "first class" in a given programming language, and why? In what do they differ from languages where they are not?
...