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What is causing ERROR: there is no unique constraint matching given keys for referenced table?
...R: there is no unique constraint matching given keys for referenced table, and having stared at it for while now I can't figure out why this error arises in this situation.
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Are Duplicate HTTP Response Headers acceptable?
...ication about whether duplicate HTTP response headers are allowed by the standard, but I need to know if this will cause compatibility issues.
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Extension methods must be defined in a non-generic static class
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The class which defines an extension method must be non-generic, static and non-nested
Every extension method must be a static method
The first parameter of the extension method should use the this keyword.
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How can I capture the result of var_dump to a string?
...Inwdr I've only ever used var_dump as a convenience feature for debugging, and have certainly never left var_dump statements in production code. I imagine this is typical. In those circumstances, performance is unlikely to be at all relevant.
– Mark Amery
Feb 2...
How to detect when WIFI Connection has been established in Android?
...that a valid network connection for HTTP exists. What should I listen for and what additional tests do I need to make to know that a valid connection exists.
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String Concatenation using '+' operator
Looking at the string class metadata, I only see the operators == and != overloaded. So how is it able to perform concatenation for the ' + ' operator?
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What is the difference between pull and clone in git?
What is the difference between doing (after mkdir repo and cd repo ):
11 Answers
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in iPhone App How to detect the screen resolution of the device
...ays this will return a 1.0f, while Retina Display devices will give a 2.0f and the iPhone 6 Plus (Retina HD) will give a 3.0f.
Now if you want to get the pixel width & height of the iOS device screen you just need to do one simple thing.
CGSize screenSize = CGSizeMake(screenBounds.size.width *...
Add comma to numbers every three digits
... Works perfectly! Thanks to Paul Creasey for simply, elegant code and thanks to Doug Neiner for putting it in plugin format. Credit given to both.
– Steve
Jan 2 '10 at 4:31
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Storing SHA1 hash values in MySQL
...d just waste an additional byte for the length of the fixed-length field.
And I also wouldn’t store the value the SHA1 is returning. Because it uses just 4 bit per character and thus would need 160/4 = 40 characters. But if you use 8 bit per character, you would only need a 160/8 = 20 character l...