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Why use symbols as hash keys in Ruby?
...lso saves memory, because they are only stored once.
Ruby Symbols are immutable (can't be changed), which makes looking something up much easier
Short(ish) answer:
Using symbols not only saves time when doing comparisons, but also saves memory, because they are only stored once.
Symbols in Ruby ...
Converting Storyboard from iPhone to iPad
...e background for everything).
EDIT: It seems the default background for UITableView in the Attributes inspector is rather strange. I had to manually set the background to "Group Table View Background Color" for grouped table views, and "White Color" for non-grouped table views. It then was displa...
how to get the host url using javascript from the current page
... Good. But what happens when the MDN guys update the browser compatibility table, which happens pretty often with newer browser releases. You might need to keep on updating this to sync with their table ;).
– kabirbaidhya
Apr 5 '17 at 5:38
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How to fix the Hibernate “object references an unsaved transient instance - save the transient insta
... I got this issue specifically when I used @Inheritance, in this case TABLE_PER_CLASS, I was referencing a subclass. CascadeType.ALL fixed it.
– Jim ReesPotter
Mar 17 '18 at 21:08
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SQL Server Restore Error - Access is Denied
I created a database on my local machine and then did a backup called tables.bak of table DataLabTables .
19 Answers
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Where can I find a list of scopes for Google's OAuth 2.0 API? [closed]
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Google's oauth docs display a table that lists all of the available scopes.
https://developers.google.com/+/api/oauth#scopes-table
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How do I escape a single quote?
...ve list, see the W3C HTML5 Named Character References or the HTML entities table on WebPlatform.org.
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What does the ^ operator do in Java?
... 6 = 110
------------------ xor
3 = 011
This the truth table for bitwise (JLS 15.22.1) and logical (JLS 15.22.2) xor:
^ | 0 1 ^ | F T
--+----- --+-----
0 | 0 1 F | F T
1 | 1 0 T | T F
More simply, you can also think of xor as "this or that, but not both!".
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How to get the HTML for a DOM element in javascript
...nless myElement is an element that can't be a child of a div, like an li, table row or table cell and so on.
– RobG
Jun 22 '11 at 4:23
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How does facebook, gmail send the real time notification?
...oblems away. In terms of PHP, you could simply poll an event log database table in your PHP script, and only return to the client when something happens? There are, I expect, many ways of implementing this.
Implementing:
Server Side:
There appear to be a few implementations of comet libraries in...