大约有 40,000 项符合查询结果（耗时：0.0285秒） [XML]
What's the difference between Ruby's dup and clone methods?
..., name: "Favorites">
clone creates a new object with the same id, so all the changes made to that new object will overwrite the original record if hitting .save
category2 = category.clone
#=> #<Category id: 1, name: "Favorites">
...
In Python, how do I iterate over a dictionary in sorted key order?
...ems() creates a list and therefore uses memory, whereas iteritems() essentially does not use memory. What to use mostly depend on the size of the dictionary. Furthermore, the automatic Python 2 to Python 3 conversion tool (2to3) automatically takes care of the conversion from iteritems() to items(),...
How do I make class methods / properties in Swift?
...
They are called type properties and type methods and you use the class or static keywords.
class Foo {
var name: String? // instance property
static var all = [Foo]() // static type property
class var comp: In...
Is it possible to modify variable in python that is in outer, but not global, scope?
...a list, or dict), and mutate the value instead of reassign.
example:
def foo():
a = []
def bar():
a.append(1)
bar()
bar()
print a
foo()
Outputs:
[1, 1]
share
|
imp...
Java Name Hiding: The Hard Way
... of working with the reflection API.
The downside is that this code is really horrible! For me, it generates a warning, and that's a good thing in general. But since it's working around a problem that is otherwise thoroughly impractical, adding a
@SuppressWarnings("static-access")
at an approp...
C# namespace alias - what's the point?
... name from different assemblies - rare, but useful to be supported.
Actually, I can see another use: when you want quick access to a type, but don't want to use a regular using because you can't import some conflicting extension methods... a bit convoluted, but... here's an example...
namespace ...
Mercurial — revert back to old version and continue from there
I'm using Mercurial locally for a project (it's the only repo there's no pushing/pulling to/from anywhere else).
7 Answers
...
Passing an array by reference
How does passing a statically allocated array by reference work?
5 Answers
5
...
Create an enum with string values
...vide a reliable and safe experience for named string values (which is partially what enums are used for).
type Options = "hello" | "world";
var foo: Options;
foo = "hello"; // Okay
foo = "asdf"; // Error!
More : https://www.typescriptlang.org/docs/handbook/advanced-types.html#string-literal-typ...
MySQL: selecting rows where a column is null
...
NULL = NULL is not really FALSE - it's NULL again. But it's not TRUE either, so IF(NULL = NULL) won't execute.
– Konerak
Jan 12 '11 at 19:50
...