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Understanding :source option of has_one/has_many through of Rails
...ular, to represent the model name, instead of :breeds which represents the table name? E.g. has_many :dog_breeds, :through => :dogs, :source => :breed (no s suffixing :breed)?
– LazerSharks
Dec 30 '14 at 22:22
...
Effect of a Bitwise Operator on a Boolean in Java
...| have different precedence from & and |.
Extract from the precedence table (with highest precedence at the top).
bitwise AND &
bitwise exclusive OR ^
bitwise inclusive OR |
logical AND &&
logical OR ||
What this mean...
What are bitwise operators?
...
It is worth noting that the single-bit truth tables listed as other answers work on only one or two input bits at a time. What happens when you use integers, such as:
int x = 5 & 6;
The answer lies in the binary expansion of each input:
5 = 0 0 0 0 0 1 0 1
&am...
What does axis in pandas mean?
...me2 on top of dataframe1 or vice a versa.
E.g making a pile of books on a table or floor
axis=1 means along "columns". It's a column-wise operation.
Suppose, to perform concat() operation on dataframe1 & dataframe2,
we will take out the 1st complete column(a.k.a 1st series) of dataframe1 an...
Are JavaScript strings immutable? Do I need a “string builder” in JavaScript?
Does javascript use immutable or mutable strings? Do I need a "string builder"?
10 Answers
...
Why C# implements methods as non-virtual by default?
...erformance concern because every method call must use the object's Virtual Table. Moreover, this strongly limits the Just-In-Time compiler's ability to inline methods and perform other kinds of optimization.
3- Most importantly, if methods are not virtual by default, you can guarantee the behavior ...
Entity Framework .Remove() vs. .DeleteObject()
...n satisfied, requires every value of one attribute (column) of a relation (table) to exist as a value of another attribute in a different (or the same) relation (table), so when relationship is Optional we break the data Integrity rule
– Mohammadreza
Jul 15 '14...
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...also sparseMatrix within the Matrix package, as seen here: R - convert BIG table into matrix by column names
with(tmp, sparseMatrix(i = as.numeric(x), j=as.numeric(y), x=z,
dimnames=list(levels(x), levels(y))))
## 2 x 3 sparse Matrix of class "dgCMatrix"
## a b c
## x 1 2 3...
Overloading Macro on Number of Arguments
...t << "i = " << i << endl;
return 0;
}
Run:
User@Table 13:06:16 /c/T
$ g++ test_overloaded_macros.cpp
User@Table 13:16:26 /c/T
$ ./a.exe
counter = 3
counter = 4
abc = 0
abc = 1
abc = 2
abc = 3
i = 0
i = 1
i = 2
i = 100
i = 101
i = 102
Note that having both _OVR and _OVR...
How to get all child inputs of a div element (jQuery)
...ry/1.11.1/jquery.min.js"></script>
<div id="panel">
<table>
<tr>
<td><input id="Search_NazovProjektu" type="text" value="Naz Val" /></td>
</tr>
<tr>
<td><input id="Search_Popis" type="text" value="Po...