大约有 15,000 项符合查询结果（耗时：0.0416秒） [XML]
How to map with index in Ruby?
...in 1.8.7+), which mixes in Enumerable, so you can call map, select, reject etc. on it just like on an array, hash, range etc.
– sepp2k
Jan 15 '11 at 1:45
9
...
What is the purpose of willSet and didSet in Swift?
...stored property.
This is useful for sending notifications, synchronisation etc... (see example below)
Example 5. Concrete Example - ViewController Container
//Underlying instance variable (would ideally be private)
var _childVC : UIViewController? {
willSet {
//REMOVE OLD VC
pr...
Entity Framework is Too Slow. What are my options? [closed]
...k at the SQL generated, use debuggers, pre-compile, take many extra steps, etc. i.e. waste a lot of time. No one says - Simplify! Everyone wants to comlicate things further by taking even more steps (wasting time).
A common sense approach would be not to use EF or LINQ at all. Use plain SQL. Th...
Finding all cycles in a directed graph
... 1 then there is an infinite number of those. For example A-B-A, A-B-A-B-A etc. Or it may be possible to join together 2 cycles into an 8-like cycle etc., etc... The meaningful approach is to look for all so called simple cycles - those that do not cross themselves except in the start/end point. The...
Understanding MongoDB BSON Document size limit
...s file metadata.
You can use this method to store images, files, videos, etc in the database much as you might in a SQL database. I have used this to even store multi gigabyte video files.
share
|
...
What is the difference between supervised learning and unsupervised learning? [closed]
...is (round skin-like-colored disk, with dark area where you expect the eyes etc). A machine learning algorithm would not have such coded definition, but would "learn-by-examples": you'll show several images of faces and not-faces and a good algorithm will eventually learn and be able to predict wheth...
How do I add tab completion to the Python shell?
...e.py shell , I get an InteractiveConsole shell - I can use tab completion, etc.
9 Answers
...
HTML minification? [closed]
...s much more likely that compression, cache management, image optimization, etc will make a bigger difference to the performance of your site overall. Those tools will show you what the biggest problems are -- if you've dealt with them all and still find that HTML minification makes a significant di...
Android screen size HDPI, LDPI, MDPI [duplicate]
...
320dp: a typical phone screen (240x320 ldpi, 320x480 mdpi, 480x800 hdpi, etc).
480dp: a tweener tablet like the Streak (480x800 mdpi).
600dp: a 7” tablet (600x1024 mdpi).
720dp: a 10” tablet (720x1280 mdpi, 800x1280 mdpi, etc).
...
Why are dashes preferred for CSS selectors / HTML attributes?
...ff you do with JavaScript these days, you'd want to use CSS Selectors for fetching elements from the DOM anyway, which makes the whole dot notation rather useless. Which one would you prefer?
var firstName = $('#first-name');
var firstName = document.querySelector('#first-name');
var firstName = do...