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Why doesn't Java Map extend Collection?
...being a particularly useful abstraction. For example:
Set<Map.Entry<String,String>>
would allow:
set.add(entry("hello", "world"));
set.add(entry("hello", "world 2");
(assuming an entry() method that creates a Map.Entry instance)
Maps require unique keys so this would violate this....
Pass all variables from one shell script to another?
...
Also it is important to note that "" are necessary if we pass multiword strings.
Taking one more example
master.sh
#!/bin/bash
echo in master.sh
var1="hello world"
sh slave1.sh $var1
sh slave2.sh "$var1"
echo back to master
slave1.sh
#!/bin/bash
echo in slave1.sh
echo value :$1
slave2.sh
...
What exactly is metaprogramming?
...not in the trivial sense
that the source files contain
characters, and strings are one of the
data types supported by the language.
Lisp code, after it's read by the
parser, is made of data structures
that you can traverse.
If you understand how compilers work,
what's really going...
Does a finally block run even if you throw a new Exception?
...s executes.
public class ExceptionTest {
public static void someFunction(String input) throws Exception {
try {
if( input.equals("ABC") ) {
System.out.println("Matched");
}
} catch (Exception e) {
throw new Exception(e);
} finally {
System.ou...
Unique combination of all elements from two (or more) vectors
...sing, which works better than the classic expand.grid function because (1) strings are not converted into factors and (2) the sorting is more intuitive:
library(tidyr)
a <- c("ABC", "DEF", "GHI")
b <- c("2012-05-01", "2012-05-02", "2012-05-03", "2012-05-04", "2012-05-05")
crossing(a, b)
# ...
Multiple commands in gdb separated by some sort of delimiter ';'?
...active if the command
# that invoked them is interactive.
# to_string is false. We just want to write the output of the commands, not capture it.
gdb.execute(fragment, from_tty=from_tty, to_string=False)
print()
Cmds()
end
example invocation:
$ gdb
(gdb) cmds echo hi ; e...
How do I catch a PHP fatal (`E_ERROR`) error?
... because processing should not typically be recovered after a fatal error. String matching an output buffer (as suggested by the original post the technique described on PHP.net) is definitely ill-advised. It's simply unreliable.
Calling the mail() function from within an error handler method prove...
How do I specify “close existing connections” in sql script
...ECLARE @dbId int
DECLARE @isStatAsyncOn bit
DECLARE @jobId int
DECLARE @sqlString nvarchar(500)
SELECT @dbId = database_id,
@isStatAsyncOn = is_auto_update_stats_async_on
FROM sys.databases
WHERE name = 'db_name'
IF @isStatAsyncOn = 1
BEGIN
ALTER DATABASE [db_name] SET AUTO_UPDATE_STAT...
What are all the possible values for HTTP “Content-Type” header?
...attribute "=" value
attribute := token
value := token / quoted-string
token := 1*
tspecials := "(" / ")" / "<" / ">" / "@" ; Must be in
/ "," / ";" / ":" / "\" / <"> ; quoted-string,
/ "/" / "[" / "]" / "?" / "." ; to use within
...
How do PHP sessions work? (not “how are they used?”)
...ssions files is the content of $_SESSION, serialized (ie, represented as a string -- with a function such as serialize) ; and is un-serialized when the file is loaded by PHP, to populate the $_SESSION array.
Sometimes, the session id is not stored in a cookie, but sent in URLs, too -- but that's q...