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Is null check needed before calling instanceof?
...tion, section 15.20.2, "Type comparison operator instanceof":
"At run time, the result of the
instanceof operator is true if the
value of the RelationalExpression is
not null and the reference could be
cast to the ReferenceType
without raising a ClassCastException.
Otherwise the res...
How to replace all occurrences of a character in string?
...ences of the string to be replaced. string::replace() would be called many times which causes lots of string copies. See my solution which addresses that problem.
– minastaros
Apr 21 '15 at 6:44
...
What encoding/code page is cmd.exe using?
...
Yes, it’s frustrating—sometimes type and other programs
print gibberish, and sometimes they do not.
First of all, Unicode characters will only display if the
current console font contains the characters. So use
a TrueType font like Lucida Console ins...
What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...target interface. In other words: the type is not changed, but the compile-time type is.
When the source object does not implement the target interface, the source object is converted into an object that implements the target interface. So both the type and the compile-time type are changed.
Let ...
How to get current time and date in C++?
Is there a cross-platform way to get the current date and time in C++?
24 Answers
24
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java.sql.SQLException: - ORA-01000: maximum open cursors exceeded
...nsactions. A connection can have only a single transaction open at any one time (but transactions can be nested)
A JDBC ResultSet is supported by a single cursor on the database. When close() is called on the ResultSet, the cursor is released.
A JDBC CallableStatement invokes a stored procedure on t...
Generating random number between 1 and 10 in Bash Shell Script [duplicate]
...
@ads20000 The docs say so, man bash, "Each time this parameter is referenced, a random integer between 0 and 32767 is generated." Note that this is not a bash error, it's an error of the implementer. Assuming bash implemented $RANDOM correctly, there should be a fai...
Profiling Vim startup time
...
If you're using Vim 7.2.269 or later, then there's the --startuptime option you can use.
vim --startuptime vim.log
from the help (vim -h):
--startuptime <file> Write startup timing messages to <file>
...
What is the curiously recurring template pattern (CRTP)?
...xample. If you use virtual method the program will know what execute in runtime. Implementing CRTP the compiler is which decide in compile time!!! This is a great performance!
template <class T>
class Writer
{
public:
Writer() { }
~Writer() { }
void write(const char* str) con...
How to import data from mongodb to pandas?
...
I tried Monary, but it is taking a lot of time. Am I missing some optimization? Tried client = Monary(host, 27017, database="db_tmp") columns = ["col1", "col2"] data_type = ["int64", "int64"] arrays = client.query("db_tmp", "coll", {}, columns, data_type) For 5...