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Why covariance and contravariance do not support value type
...or not.
You might want to read Eric Lippert's blog post on representation and identity for more on this topic in general.
EDIT: Having reread Eric's blog post myself, it's at least as much about identity as representation, although the two are linked. In particular:
This is why covariant and ...
How may I sort a list alphabetically using jQuery?
I'm a bit out of my depth here and I'm hoping this is actually possible.
10 Answers
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Difference between pre-increment and post-increment in a loop?
Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?
22 Answers
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Wget output document and headers to STDOUT
I'm trying to output document body and its headers to stdout with wget by wget -S -O - http://google.com
5 Answers
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How can I force division to be floating point? Division keeps rounding down to 0?
I have two integer values a and b , but I need their ratio in floating point. I know that a < b and I want to calculate a / b , so if I use integer division I'll always get 0 with a remainder of a .
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How do you detect Credit card type based on number?
...gy in some documents). These six digits are subject to an international standard, ISO/IEC 7812, and can be used to determine the type of card from the number.
Unfortunately the actual ISO/IEC 7812 database is not publicly available, however, there are unofficial lists, both commercial and free, in...
Validate phone number with JavaScript
I found this code in some website, and it works perfectly. It validates that the phone number is in one of these formats:
(123) 456-7890 or 123-456-7890
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How do I convert a String object into a Hash object?
...en its string representation is "{:a=>#<Object:0x7f66b65cf4d0>}", and I can't use eval to turn it back into a hash because #<Object:0x7f66b65cf4d0> isn't valid Ruby syntax.
However, if all that's in the hash is strings, symbols, numbers, and arrays, it should work, because those have...
Read input from console in Ruby?
...ing like that?
Update
Kernel.gets tries to read the params found in ARGV and only asks to console if not ARGV found. To force to read from console even if ARGV is not empty use STDIN.gets
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mongodb: insert if not exists
...-find-else-update block entirely. It will insert if the key doesn't exist and will update if it does.
Before:
{"key":"value", "key2":"Ohai."}
After:
{"key":"value", "key2":"value2", "key3":"value3"}
You can also specify what data you want to write:
data = {"$set":{"key2":"value2"}}
Now yo...