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“for” vs “each” in Ruby
...
Never ever use for it may cause almost untraceable bugs.
Don't be fooled, this is not about idiomatic code or style issues. Ruby's implementation of for has a serious flaw and should not be used.
Here is an example where for introduces a bug,
class Library
def initialize
@ary = []
...
how does array[100] = {0} set the entire array to 0?
...d the initialiser.
If your array is auto, then it is another story.
int foo(void)
{
char array[100] = {0};
...
}
In this case at every call of the function foo you will have a hidden memset.
The code above is equivalent to
int foo(void)
{
char array[100];
memset(array, 0, sizeof(array));
.....
How do I dump an object's fields to the console?
...
The to_yaml method seems to be useful sometimes:
$foo = {:name => "Clem", :age => 43}
puts $foo.to_yaml
returns
---
:age: 43
:name: Clem
(Does this depend on some YAML module being loaded? Or would that typically be available?)
...
Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)
...s not efficiency. Non-reentrant mutexes lead to better code.
Example: A::foo() acquires the lock. It then calls B::bar(). This worked fine when you wrote it. But sometime later someone changes B::bar() to call A::baz(), which also acquires the lock.
Well, if you don't have recursive mutexes,...
Log all requests from the python-requests module
...level=logging.DEBUG)
>>> r = requests.get('http://httpbin.org/get?foo=bar&baz=python')
DEBUG:urllib3.connectionpool:Starting new HTTP connection (1): httpbin.org:80
DEBUG:urllib3.connectionpool:http://httpbin.org:80 "GET /get?foo=bar&baz=python HTTP/1.1" 200 366
Depending on the e...
How do I get the object if it exists, or None if it does not exist?
... python is to wrap it in a try catch:
try:
go = SomeModel.objects.get(foo='bar')
except SomeModel.DoesNotExist:
go = None
What I did do, is to subclass models.Manager, create a safe_get like the code above and use that manager for my models. That way you can write: SomeModel.objects.safe_...
Does static constexpr variable inside a function make sense?
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An example for my last comment: static constexpr int foo = 100;. There is no reason why the compiler couldn't substitute usage of foo everywhere for literal 100, unless code were doing something like &foo. So static on foo has no usefulness in this case since foo doesn't ex...
What does the “static” modifier after “import” mean?
... fields / method of a class instead of:
package test;
import org.example.Foo;
class A {
B b = Foo.B_INSTANCE;
}
You can write :
package test;
import static org.example.Foo.B_INSTANCE;
class A {
B b = B_INSTANCE;
}
It is useful if you are often used a constant from another class in yo...
Getting URL hash location, and using it in jQuery
...n use the String.substring method:
var url = "http://example.com/file.htm#foo";
var hash = url.substring(url.indexOf('#')); // '#foo'
Advice: Be aware that the user can change the hash as he wants, injecting anything to your selector, you should check the hash before using it.
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Best practice: PHP Magic Methods __set and __get [duplicate]
...
@Matthieu: As noted in the answer, $foo->bar would simply call $this->get_bar(), which is a getter and can be changed to do whatever you need it to.
– FtDRbwLXw6
Feb 13 '13 at 0:09
...