大约有 44,000 项符合查询结果（耗时：0.0422秒） [XML]
String vs. StringBuilder
...ance difference is significant. See the KB article "How to improve string concatenation performance in Visual C#".
I have always tried to code for clarity first, and then optimize for performance later. That's much easier than doing it the other way around! However, having seen the enormous perfo...
Why doesn't Dictionary have AddRange?
...hods let you pass in IEqualityComparer when relevant: var combined = dict1.Concat(dict2).GroupBy(kvp => kvp.Key, dict1.Comparer).ToDictionary(grp => grp.Key, grp=> grp.First(), dict1.Comparer);
– Kyle McClellan
Mar 20 '18 at 19:32
...
Which is the preferred way to concatenate a string in Python?
Since Python's string can't be changed, I was wondering how to concatenate a string more efficiently?
12 Answers
...
What is the best way to concatenate two vectors?
...
Depends on whether you really need to physically concatenate the two vectors or you want to give the appearance of concatenation of the sake of iteration. The boost::join function
http://www.boost.org/doc/libs/1_43_0/libs/range/doc/html/range/reference/utilities/join.html
...
Tab space instead of multiple non-breaking spaces (“nbsp”)?
...
Was looking for this when building a large concat() query in MySQL for use in a Crystal Report. the ASCII (	) did the job perfectly!
– MikeMighty
Mar 9 '18 at 14:40
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Initialization of an ArrayList in one line
...e:
Stream<String> strings = Stream.of("foo", "bar", "baz");
You can concatenate Streams:
Stream<String> strings = Stream.concat(Stream.of("foo", "bar"),
Stream.of("baz", "qux"));
Or you can go from a Stream to a List:
import static java.util.strea...
Listing all permutations of a string/integer
...ment.
The permutation of a set of elements is a list each of the elements, concatenated with every permutation of the other elements.
Example:
If the set just has one element -->
return it.
perm(a) -> a
If the set has two characters: for
each element in it: return the
element, with the permut...
How to declare variable and use it in the same Oracle SQL script?
...
Is it possible to concatenate variables+strings?
– Ecropolis
Jun 18 '14 at 15:01
...
What reason is there to use null instead of undefined in JavaScript?
...eed to make different falsy checks. It would not be the last time that you concat a null object to a string and get a "null" as a string. Or passing a 0 as numeric value and wondering why the IF statement handles is t as a false.
– com2ghz
Feb 11 '16 at 9:29
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Fastest Way to Find Distance Between Two Lat/Long Points
...find the values:
SELECT *
FROM table
WHERE MBRContains(LineFromText(CONCAT(
'('
, @lon + 10 / ( 111.1 / cos(RADIANS(@lon)))
, ' '
, @lat + 10 / 111.1
, ','
, @lon - 10 / ( 111.1 / cos(RADIANS(@lat)))
, ' '
, @lat - 10 / 111.1
...