大约有 31,400 项符合查询结果（耗时：0.0373秒） [XML]
What exactly is metaprogramming?
...gram can examine information about itself. For example returning a list of all the properties of an object.
In languages like ActionScript, you can evaluate functions at runtime to create new programs such as eval("x" + i). DoSomething() would affect an object called x1 when i is 1 and x2 when i is...
'innerText' works in IE, but not in Firefox
...current beta release, and has been in aurora for a while. What this practically means is you can start developing sites using innerText only and expect it to work (with possible quirks) on all current browsers in the near future, and old-IE too.
– Bob
Feb 22 '1...
Android screen size HDPI, LDPI, MDPI [duplicate]
I have a background that I need fit in all screen sizes. I have three folders, hdpi , ldpi and mdpi for drawables, but in the emulator there isn't any referense to what resolution hdpi is and what mdpi and ldpi are.
...
How to check if an array field contains a unique value or another array in MongoDB?
...
db.blogpost.find({ 'tags' : 'tag1'}); //1
db.blogpost.find({ 'tags' : { $all : [ 'tag1', 'tag2' ] }}); //2
db.blogpost.find({ 'tags' : { $in : [ 'tag3', 'tag4' ] }}); //3
share
|
improve this ans...
Volatile vs. Interlocked vs. lock
...
Worst (won't actually work)
Change the access modifier of counter to public volatile
As other people have mentioned, this on its own isn't actually safe at all. The point of volatile is that multiple threads running on multiple CPUs can and...
Why do some claim that Java's implementation of generics is bad?
I've occasionally heard that with generics, Java didn't get it right. (nearest reference, here )
13 Answers
...
How to list the tables in a SQLite database file that was opened with ATTACH?
....schema tablename
Print the entire table:
SELECT * FROM tablename;
List all of the available SQLite prompt commands:
.help
share
|
improve this answer
|
follow
...
How to run a single RSpec test?
...
Usually I do:
rspec ./spec/controllers/groups_controller_spec.rb:42
Where 42 represents the line of the test I want to run.
EDIT1:
You could also use tags. See here.
EDIT 2:
Try:
bundle exec rspec ./spec/controllers/gro...
Can I install Python windows packages into virtualenvs?
Virtualenv is great: it lets me keep a number of distinct Python installations so that different projects' dependencies aren't all thrown together into a common pile.
...
Comparing date ranges
...
This is a classical problem, and it's actually easier if you reverse the logic.
Let me give you an example.
I'll post one period of time here, and all the different variations of other periods that overlap in some way.
|-------------------| com...