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Build vs new in Rails 3
... of any Firm's id at all, so it needs the firm_id passed to it.
The only difference between some_firm.clients.new and some_firm.clients.build seems to be that build also adds the newly-created client to the clients collection:
henrym:~/testapp$ rails c
Loading development environment (Rails 3.0.4)...
How to succinctly write a formula with many variables from a data frame?
...
There is a special identifier that one can use in a formula to mean all the variables, it is the . identifier.
y <- c(1,4,6)
d <- data.frame(y = y, x1 = c(4,-1,3), x2 = c(3,9,8), x3 = c(4,-4,-2))
mod <- lm(y ~ ., data = d)
You can also d...
Where is Maven' settings.xml located on mac os?
...
If you use brew to install maven, then the settings file should be in
/usr/local/Cellar/maven/<version>/libexec/conf
share
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Why specify @charset “UTF-8”; in your CSS file?
...
It tells the browser to read the css file as UTF-8. This is handy if your CSS contains unicode characters and not only ASCII.
Using it in the meta tag is fine, but only for pages that include that meta tag.
Read about the rules for character set resolution of CSS files at the w3c spec for...
Difference between two dates in Python
I have two different dates and I want to know the difference in days between them. The format of the date is YYYY-MM-DD.
5 ...
Deleting all files from a folder using PHP?
...mp/*'); // get all file names
foreach($files as $file){ // iterate files
if(is_file($file))
unlink($file); // delete file
}
If you want to remove 'hidden' files like .htaccess, you have to use
$files = glob('path/to/temp/{,.}*', GLOB_BRACE);
...
Why is it important to override GetHashCode when Equals method is overridden?
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Yes, it is important if your item will be used as a key in a dictionary, or HashSet<T>, etc - since this is used (in the absence of a custom IEqualityComparer<T>) to group items into buckets. If the hash-code for two items does not ma...
What is the real overhead of try/catch in C#?
...ect this happens only when the exception is thrown (but I don't know), and if so, this would be decently sized hidden cost every time an exception is thrown... so it's not like you are just jumping from one place in the code to another, there is a lot going on.
I don't think it's a problem as long ...
C# Sortable collection which allows duplicate keys
...ompare(TKey x, TKey y)
{
int result = x.CompareTo(y);
if (result == 0)
return 1; // Handle equality as beeing greater
else
return result;
}
#endregion
}
You will use it when instancing a new SortedList, SortedDictionary etc:
SortedLi...
Understanding Linux /proc/id/maps
... - This describes how pages in the region can be accessed. There are four different permissions: read, write, execute, and shared. If read/write/execute are disabled, a - will appear instead of the r/w/x. If a region is not shared, it is private, so a p will appear instead of an s. If the process at...