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What is the instanceof operator in JavaScript?
...ce p inherits from Person.prototype.
Per the OP's request
I've added a small example with some sample code and an explanation.
When you declare a variable you give it a specific type.
For instance:
int i;
float f;
Customer c;
The above show you some variables, namely i, f, and c. The type...
Why does this loop produce “warning: iteration 3u invokes undefined behavior” and output more than 4
...
If during the evaluation of an expression, the result is not mathematically defined or not in the range of
representable values for its type, the behavior is undefined. [ Note: most existing implementations of C++
ignore integer overflows. Treatment of division by zero, forming a remainde...
MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
Efficient way to apply multiple filters to pandas DataFrame or Series
...s to apply several filters to a Pandas DataFrame or Series object. Essentially, I want to efficiently chain a bunch of filtering (comparison operations) together that are specified at run-time by the user.
...
Makefile, header dependencies
...vided by the gnu preprocessor are a bit confusing. However, the removal of all directories from the build target with -MM is documented and not a bug [gpp]:
By default CPP takes the name of the main input file, deletes any
directory components and any file suffix such as ‘.c’, and appends ...
Swift Programming: getter/setter in stored property
...the new value that you assign will replace the one that was just set.
So all you have to do is this:
var rank: Int = 0 {
didSet {
// Say 1000 is not good for you and 999 is the maximum you want to be stored there
if rank >= 1000 {
rank = 999
}
}
}
...
Why doesn't list have safe “get” method like dictionary?
...accessing list elements (as the len method is very fast). The .get method allows you to query the value associated with a name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list).
Of course, you can easily implement this yourself:
def sa...
Explaining Python's '__enter__' and '__exit__'
...
Using these magic methods (__enter__, __exit__) allows you to implement objects which can be used easily with the with statement.
The idea is that it makes it easy to build code which needs some 'cleandown' code executed (think of it as a try-finally block). Some more ex...
MongoDB Many-to-Many Association
... user document:
{name:"Joe"
,roles:["Admin","User","Engineer"]
}
To get all the Engineers, use:
db.things.find( { roles : "Engineer" } );
If you want to maintain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:...
Run an Application in GDB Until an Exception Occurs
... a C++ exception.
catch
The catching of a C++ exception.
exec
A call to exec. This is currently only available for HP-UX.
fork
A call to fork. This is currently only available for HP-UX.
vfork
A call to vfork. This is currently only available for HP-UX.
load or load libname
...