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Why is whitespace sometimes needed around metacharacters?
...@DmitriChubarov Braces are allowed in command names (including functions: {foo} () { echo hello; }. "Name", as defined in by bash as "a word consisting only of alphanumeric characters and underscores, and beginning with an alphabetic character or an underscore", applies only to var...
java: Class.isInstance vs Class.isAssignableFrom
...
clazz.isAssignableFrom(Foo.class) will be true whenever the class represented by the clazz object is a superclass or superinterface of Foo.
clazz.isInstance(obj) will be true whenever the object obj is an instance of the class clazz.
That is:
c...
Renaming table in rails
...
You would typically do this sort of thing in a migration:
class RenameFoo < ActiveRecord::Migration
def self.up
rename_table :foo, :bar
end
def self.down
rename_table :bar, :foo
end
end
share
...
Difference between “@id/” and “@+id/” in Android
...roid:id/list">
What's the difference?
.. I'm glad you asked ☺
@+id/foo means you are creating an id named foo in the namespace of your application.
You can refer to it using @id/foo.
@android:id/foo means you are referring to an id defined in the android namespace.
The '+' means to create t...
Java switch statement: Constant expression required, but it IS constant
... expression to be known at compile time to compile a switch, but why isn't Foo.BA_ constant?
While they are constant from the perspective of any code that executes after the fields have been initialized, they are not a compile time constant in the sense required by the JLS; see §15.28 Constant Ex...
How do I create a parameterized SQL query? Why Should I?
...n example of how you do parameters with Sql Server:
Public Function GetBarFooByBaz(ByVal Baz As String) As String
Dim sql As String = "SELECT foo FROM bar WHERE baz= @Baz"
Using cn As New SqlConnection("Your connection string here"), _
cmd As New SqlCommand(sql, cn)
cmd.Pa...
Asynchronous method call in Python?
...
Something like:
import threading
thr = threading.Thread(target=foo, args=(), kwargs={})
thr.start() # Will run "foo"
....
thr.is_alive() # Will return whether foo is running currently
....
thr.join() # Will wait till "foo" is done
See the documentation at https://docs.python.org/librar...
What's the best way to refactor a method that has too many (6+) parameters?
...are multiple overloaded variants, you should look at the Builder pattern:
Foo foo = new Foo()
.configBar(anything)
.configBaz(something, somethingElse)
// and so on
If it's a normal method, you should think about the relationships between the values being passed, and...
warning: incompatible implicit declaration of built-in function ‘xyz’
...;
}
Compiled like this on Fedora 17 Linux 64 bit with gcc:
el@defiant ~/foo2 $ gcc -o n n2.c
n2.c: In function ‘main’:
n2.c:2:3: warning: incompatible implicit declaration of built-in
function ‘exit’ [enabled by default]
el@d...
What is the difference between Scope_Identity(), Identity(), @@Identity, and Ident_Current()?
...PE_IDENTITY(), as opposed to the global scope of @@IDENTITY.
CREATE TABLE Foo(
ID INT IDENTITY(1,1),
Dummy VARCHAR(100)
)
CREATE TABLE FooLog(
ID INT IDENTITY(2,2),
LogText VARCHAR(100)
)
go
CREATE TRIGGER InsertFoo ON Foo AFTER INSERT AS
BEGIN
INSERT INTO FooLog (LogText) VALUES ('inser...