大约有 40,000 项符合查询结果（耗时：0.0393秒） [XML]
How is null + true a string?
...t's walk through this in turn.
X is the null type here - or not a type at all, if you want to think of it that way. It's not providing any candidates. Y is bool, which doesn't provide any user-defined + operators. So the first step finds no user-defined operators.
The compiler then moves on to the...
Manually raising (throwing) an exception in Python
...
How do I manually throw/raise an exception in Python?
Use the most specific Exception constructor that semantically fits your issue.
Be specific in your message, e.g.:
raise ValueError('A very specific bad thing happened.')
Don't ...
How to extract a git subdirectory and make a submodule out of it?
...
Nowadays there's a much easier way to do it than manually using git filter-branch: git subtree
Installation
NOTE git-subtree is now part of git (if you install contrib) as of 1.7.11, so you might already have it installed. You may check by executing git subtree.
To install...
Calling closure assigned to object property directly
...e for StdClass of course, because you cannot add the __call method)
class Foo
{
public function __call($method, $args)
{
if(is_callable(array($this, $method))) {
return call_user_func_array($this->$method, $args);
}
// else throw exception
}
}
$fo...
How to implement Enums in Ruby?
...Jun 20 '12 at 15:44
Andrew Marshall
87.3k1818 gold badges202202 silver badges204204 bronze badges
answered Sep 16 '08 at 19:32
...
Reference: mod_rewrite, URL rewriting and “pretty links” explained
...rver doesn't have to be Apache, there are many other web servers which are all just programs which run persistently and are attached to a port which respond to HTTP requests. You can write one yourself. This paragraph was intended to divorce you from any notion that URLs directly equal files, which ...
Creating the Singleton design pattern in PHP5
...
/**
* Singleton class
*
*/
final class UserFactory
{
/**
* Call this method to get singleton
*
* @return UserFactory
*/
public static function Instance()
{
static $inst = null;
if ($inst === null) {
$inst = new UserFactory();
...
How do I remove a property from a JavaScript object?
...t object, then that object will, of course, not be garbage collected until all references to it have disappeared.
delete will only work on properties whose descriptor marks them as configurable.
share
|
...
Traits in PHP – any real world examples/best practices? [closed]
...
My personal opinion is that there is actually very little application for traits when writing clean code.
Instead of using traits to hack code into a class it is better to pass in the dependencies via the constructor or via setters:
class ClassName {
protected...
How to check if a map contains a key in Go?
...ring) and ok will receive a bool that will be set to true if "foo" was actually present in the map
evaluates ok, which will be true if "foo" was in the map
If "foo" is indeed present in the map, the body of the if statement will be executed and val will be local to that scope.
...