大约有 44,000 项符合查询结果（耗时：0.0540秒） [XML]
How to map and remove nil values in Ruby
...blem:
N = 1_00_000
enum = 1.upto(1_000)
Benchmark.bmbm do |x|
x.report("select + map") { N.times { enum.select { |i| i.even? }.map{|i| i + 1} } }
x.report("map + compact") { N.times { enum.map { |i| i + 1 if i.even? }.compact } }
x.report("filter_map") { N.times { enum.filter_map { |i| i ...
How do I interactively unstage a particular hunk in git?
...
@Nawaz: That's correct - git add -p filename selectively stages changes from that file, and git reset -p filename selectively unstages changes. There's also git checkout -p -- filename, which lets you selectively discard changes from a file. Warning: each of add and res...
Named capturing groups in JavaScript regex?
...if the order of the groups changes? Also, it's annonying to put this extra chars on the other groups...
– Alba Mendez
Nov 9 '12 at 15:45
...
Resolving LNK4098: defaultlib 'MSVCRT' conflicts with
...ry time I want to create an application in VC++.
Right-click the project, select Properties then under 'Configuration properties | C/C++ | Code Generation', select "Multi-threaded Debug (/MTd)" for Debug configuration.
Note that this does not change the setting for your Release configuration - you...
How do you list all triggers in a MySQL database?
...w triggers;
or you can access the INFORMATION_SCHEMA table directly by:
select trigger_schema, trigger_name, action_statement
from information_schema.triggers
You can do this from version 5.0.10 onwards.
More information about the TRIGGERS table is here.
...
Get specific object by id from array of objects in AngularJS
... };
// We filter the array by id, the result is an array
// so we select the element 0
single_object = $filter('filter')(foo.results, function (d) {return d.id === 2;})[0];
// If you want to see the result, just check the log
console.log(single_object);
}]);
Plunker: http://...
Datetime equal or greater than today in MySQL
...
SELECT * FROM users WHERE created >= CURDATE();
But I think you mean created < today
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Meaning of $? (dollar question mark) in shell scripts
...k() == 0) {
/* Call false. */
execl("./false", "./false", (char *)NULL);
}
int status;
/* Wait for a child to finish. */
wait(&status);
/* Status encodes multiple fields,
* we need WEXITSTATUS to get the exit status:
* http://stackoverflow.com/questi...
How to get a number of random elements from an array?
...- Math.random());
// Get sub-array of first n elements after shuffled
let selected = shuffled.slice(0, n);
DEMO:
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Best way to test SQL queries [closed]
...value, and all values are consecutive:
create view cm_absolute_month as
select *, year * 12 + month as absolute_month from month_value;
Now what we have to test is inherent in our spec, namely that for any tuple (year, month), there is one and only one (absolute_month), and that (absolute_month...