大约有 40,000 项符合查询结果（耗时：0.0522秒） [XML]
What are the differences between a HashMap and a Hashtable in Java?
...shMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.
Hashtable does not allow null keys or values. HashMap allows one null key and any number of null values.
One of HashMap's subclasses is LinkedHashMap, so in the event that you'd wa...
What is a stack trace, and how can I use it to debug my application errors?
...
In simple terms, a stack trace is a list of the method calls that the application was in the middle of when an Exception was thrown.
Simple Example
With the example given in the question, we can determine exactly where the exception was thrown in the application. Let's have a lo...
ctypes - Beginner
...o testlib.so -fPIC testlib.c
# or... for Mac OS X
$ gcc -shared -Wl,-install_name,testlib.so -o testlib.so -fPIC testlib.c
Then, write a wrapper using ctypes:
testlibwrapper.py
import ctypes
testlib = ctypes.CDLL('/full/path/to/testlib.so')
testlib.myprint()
Now execute it:
$ python testlibwrap...
Is the “struct hack” technically undefined behavior?
...rictly conforming with the C Standard, although it does seem to work under all known implementations. (Compilers which check array bounds carefully might issue warnings.)
The rationale behind the 'strictly conforming' bit is in the spec, section J.2 Undefined behavior, which includes in the list o...
UPDATE multiple tables in MySQL using LEFT JOIN
I have two tables, and want to update fields in T1 for all rows in a LEFT JOIN.
5 Answers
...
How to loop through a HashMap in JSP?
...ose <% %> things) are considered a poor practice. I recommend to install JSTL (just drop the JAR file in /WEB-INF/lib and declare the needed taglibs in top of JSP). It has a <c:forEach> tag which can iterate over among others Maps. Every iteration will give you a Map.Entry back which in ...
How to generate gcc debug symbol outside the build target?
...R=Joe Developer joe.developer@somewhere.com
VCS: COMMIT_DATE=2013-12-19
All that is left is to check-out the original code, re-compile without optimizations, and start debugging.
share
|
im...
What is an existential type?
...hrough the Wikipedia article Existential types . I gathered that they're called existential types because of the existential operator (∃). I'm not sure what the point of it is, though. What's the difference between
...
How to send a correct authorization header for basic authentication
...
This doesn't answer the question at all. Passing it as a url is not a header.
– jemiloii
Jan 29 '15 at 19:06
5
...
Is it better to reuse a StringBuilder in a loop?
...refully in a while (45 mins). Note that doing concatenation in the append calls reduces the point of using StringBuilder in the first place somewhat :)
– Jon Skeet
Oct 28 '08 at 7:26
...