大约有 48,000 项符合查询结果（耗时：0.0325秒） [XML]
Why do Python's math.ceil() and math.floor() operations return floats instead of integers?
...nsider: If floor() returned an integer, what should floor(1.0e30) return?
Now, while Python's integers are now arbitrary precision, it wasn't always this way. The standard library functions are thin wrappers around the equivalent C library functions.
...
Using a dispatch_once singleton model in Swift
...ants (and variables), and is thread safe by the definition of let. This is now officially recommended way to instantiate a singleton.
Class constants were introduced in Swift 1.2. If you need to support an earlier version of Swift, use the nested struct approach below or a global constant.
Nested ...
Should MySQL have its timezone set to UTC?
...e server as long as you have the time set right for the current timezone, know the timezone of the datetime columns that you store, and are aware of the issues with daylight savings time.
On the other hand if you have control of the timezones of the servers you work with then you can have everythin...
Combining multiple git repositories
...f phd/figures and phd/thesis (just replace code with figures and thesis).
Now your directory structure should look like this:
phd
|_code
| |_.git
| |_code
| |_(your code...)
|_figures
| |_.git
| |_figures
| |_(your figures...)
|_thesis
|_.git
...
How to solve java.lang.NoClassDefFoundError?
...efineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java....
What is the difference between Ruby 1.8 and Ruby 1.9
...es
Performance
Threads/Fibers
Encoding/Unicode
gems is (mostly) built-in now
if statements do not introduce scope in Ruby.
What's changed?
Single character strings.
Ruby 1.9
irb(main):001:0> ?c
=> "c"
Ruby 1.8.6
irb(main):001:0> ?c
=> 99
String index.
Ruby 1.9
irb(main):0...
Open Sublime Text from Terminal in macOS
...lling, etc.) OR that Sublime Text isn't installed!
Check ".bash_profile":
Now it's time to create your symbolic link in your PATH folder, BUT, before we do, let's check your profile file by using nano ~/.bash_profile. These are the following lines that pertain to having subl work on the command lin...
iPhone App Minus App Store?
...r AccelerometerGraph.app root@jasoniphone:/Applications/
Let SpringBoard know the new application has been installed:
ssh mobile@jasoniphone.local uicache
This only has to be done when you add or remove applications. Updated applications just need to be relaunched.
To make life easier for y...
Generate a random point within a circle (uniformly)
...gle we just fold any points that appear in ADC back down to ABC along AC.
Now consider a circle. In the limit we can think of it as infinitely many isoceles triangles ABC with B at the origin and A and C on the circumference vanishingly close to each other. We can pick one of these triangles simply...
Python timedelta in years
...e date. Currently I've got timedelta from datetime module and I don't know how to convert it to years.
16 Answers
...