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Why doesn't String switch statement support a null case?
...st by Christian Hujer has some insightful speculation about why null isn't allowed in switches (although it centers on the enum switch rather than the String switch):
Under the hood, the switch statement will typically compile to a tablesswitch byte code. And the "physical" argument to switch as we...
Regular Expression to match only alphabetic characters
...z]+$/
to match an input string of ASCII alphabets.
[A-Za-z] will match all the alphabets (both lowercase and uppercase).
^ and $ will make sure that nothing but these alphabets will be matched.
Code:
preg_match('/^[A-Z]+$/i', "abcAbc^Xyz", $m);
var_dump($m);
Output:
array(0) {
}
Test cas...
How to get String Array from arrays.xml file
...c class Episode7 extends ListActivity {
String[] mTestArray;
/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create an ArrayAdapter that will contain all list ite...
Waiting until two async blocks are executed before starting another block
...
NSLog(@"Block3");
});
// only for non-ARC projects, handled automatically in ARC-enabled projects.
dispatch_release(group);
and could produce output like this:
2012-08-11 16:10:18.049 Dispatch[11858:1e03] Block1
2012-08-11 16:10:18.052 Dispatch[11858:1d03] Block2
2012-08-11 16:10:23.051 Dis...
How to create abstract properties in python abstract classes
In the following code, I create a base abstract class Base . I want all the classes that inherit from Base to provide the name property, so I made this property an @abstractmethod .
...
Reading InputStream as UTF-8
...ug that the OutputStreamWriter constructors have: only one of the four actually condescends to tell you when something goes wrong. You again have to use the fancy CharsetDecoder dec argument there, too. The only safe and sane thing to do is to consider all other constructors deprecated, because they...
How do you write a migration to rename an ActiveRecord model and its table in Rails?
...ble_name
end
end
I had to go and rename the model declaration file manually.
Edit:
In Rails 3.1 & 4, ActiveRecord::Migration::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rena...
boost多索引容器multi_index_container实战 - C/C++ - 清泛网 - 专注C/C++及内核技术
boost多索引容器multi_index_container实战boost多索引容器multi_index_container用法详解、性能测试等。目录：
boost多索引容器multi_index_container详解
boost多索引容器multi_index_container架构图
boost多索引容器multi_index_container性能测试
原文地...
Haskell Type vs Data Constructor
...erstanding type constructors and data constructors. For example, I don't really understand the difference between this:
6 A...
Explain how finding cycle start node in cycle linked list work?
...t node in the cycle.
When the tortoise and hare meet, we have found the smallest i (the number of steps taken by the tortoise) such that Xi = X2i. Let mu represent the number of steps to get from X0 to the start of the cycle, and let lambda represent the length of the cycle. Then i = mu + alambda,...