大约有 47,000 项符合查询结果（耗时：0.0837秒） [XML]
Is there any overhead to declaring a variable within a loop? (C++)
...the assignment could indeed be cheaper. Also, as we expand this discussion from ints to C++ types, one could generalize 'var=4' as some other operation than 'assign variable from a value of the same type'.
– greggo
Mar 5 '14 at 20:15
...
Is it ok to use dashes in Python files when trying to import them?
...pt including what I considered to be the most relevant bits of information from all other answers in one place
share
|
improve this answer
|
follow
|
...
Red black tree over avl tree
...od insights on differences, similarities, performance, etc.
Here's a quote from the article:
RB-Trees are, as well as AVL trees, self-balancing. Both of them provide O(log n) lookup and insertion performance.
The difference is that RB-Trees guarantee O(1) rotations per insert operation. That is wha...
What does an exclamation mark mean in the Swift language?
... value, this can be obtained by "unwrapping" the variable (obtaining the T from Some(T)).
How is john!.apartment = number73 different from john.apartment = number73? (Paraphrased)
If you write the name of an Optional variable (eg text john, without the !), this refers to the "wrapped" enum (S...
Why does Java allow us to compile a class with a name different than the file name?
...ots of single method interface implementations in their own separate files from the main class they are used in. (I'm thinking of action listeners in particular)
There is a good explanation of all nested classes in the Nested Classes Java tutorial on Oracle's website, which has examples of each. It...
String concatenation in Ruby
...g"
The second method seems to be more efficient in term of memory/speed from what I've seen (not measured though). All three methods will throw an uninitialized constant error when ROOT_DIR is nil.
When dealing with pathnames, you may want to use File.join to avoid messing up with pathname separ...
Can you nest html forms?
..., no. You can have several forms in a page but they should not be nested.
From the html5 working draft:
4.10.3 The form element
Content model:
Flow content, but with no form element descendants.
share
...
final keyword in method parameters [duplicate]
...er, if the parameter is not final, although one can reassign the parameter from the passed in argument to anything else, the caller of the function never loses its reference, and continues to point to the same object.
– Armand
Feb 20 '14 at 18:19
...
Is there a standardized method to swap two variables in Python?
...
Python evaluates expressions from left to right. Notice that while
evaluating an assignment, the right-hand side is evaluated before the
left-hand side.
http://docs.python.org/3/reference/expressions.html#evaluation-order
That means the follow...
How to check if a specified key exists in a given S3 bucket using Java
...GetObject access will not work. The reason being, Amazon will prevent you from checking for the presence of the key if you dont have ListBucket access. Just knowing whether a key is present or not, will also suffice for malicious users in some cases. Hence unless they have ListBucket access they wi...