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Classes vs. Modules in VB.NET
...nly way for instance to implement an extension method in VB.Net.
There is one huge difference between Modules and Classes with Static Members. Any method defined on a Module is globally accessible as long as the Module is available in the current namespace. In effect a Module allows you to define...
When would you use a WeakHashMap or a WeakReference?
...
One problem with strong references is
caching, particular with very large
structures like images. Suppose you
have an application which has to work
with user-supplied images, like the
web site design tool I work on....
The SQL OVER() clause - when and why is it useful?
...use.
The PARTITION BY clause let's you break up your aggregate functions. One obvious and useful example would be if you wanted to generate line numbers for order lines on an order:
SELECT
O.order_id,
O.order_date,
ROW_NUMBER() OVER(PARTITION BY O.order_id) AS line_item_no,
OL.prod...
What does “abstract over” mean?
...onsider a program that takes the sum of the numbers 1, 2, and 3:
val sumOfOneTwoThree = 1 + 2 + 3
This program is not very interesting, since it's not very abstract. We can abstract over the numbers we're summing, by integrating all lists of numbers under a single symbol ns:
def sumOf(ns: List[I...
Why no ICloneable?
Is there a particular reason why a generic ICloneable<T> does not exist?
9 Answers
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What's the difference between encoding and charset?
...ng has a particular charset associated with it, but there can be more than one encoding for a given charset. A charset is simply what it sounds like, a set of characters. There are a large number of charsets, including many that are intended for particular scripts or languages.
However, we are w...
PG undefinedtable error relation users does not exist
...for rspec. I haven't created test yet because it's too advanced for me but one day soon i will! :P
22 Answers
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Ignore outliers in ggplot2 boxplot
... Using the above method, limits might get biassed by a small extreme on one side and and big extreme on the other, e.g. ylim <- c(-0.1, 1000) * 1.05 gives [1] 0.105 1050. To get equal limits around the mean you could use ylim + c(-0.05, 0.05) * diff(ylim) / 2. Prettier in my opinion.
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Which annotation should I use: @IdClass or @EmbeddedId
...ry. Some may argue that this differs from a more natural language like the one promoted by IdClass. But most of the times understanding right from the query that a given field is part of the composite key is of invaluable help.
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How do I get the type of a variable?
In C++, how does one find the type of a variable?
10 Answers
10
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