大约有 13,700 项符合查询结果（耗时：0.0291秒） [XML]
How to map and remove nil values in Ruby
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Ruby 2.7+
There is now!
Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your ...
Download multiple files with a single action
... * Download a list of files.
* @author speedplane
*/
function download_files(files) {
function download_next(i) {
if (i >= files.length) {
return;
}
var a = document.createElement('a');
a.href = files[i].download;
a.target = '_parent';
// Use a.downloa...
Java: PrintStream to String?
...= new ByteArrayOutputStream();
final String utf8 = StandardCharsets.UTF_8.name();
try (PrintStream ps = new PrintStream(baos, true, utf8)) {
yourFunction(object, ps);
}
String data = baos.toString(utf8);
...
How to generate an entity-relationship (ER) diagram using Oracle SQL Developer
....
Click on the «Browser» tab, expand the design (probably called Untitled_1), right-click «Relational Models» and select «New Relational Model».
Right click on the newly created relational model (probably Relational_1) and select «Show».
Then just drag the tables you want (from e.g. the «Co...
Hidden Features of C#? [closed]
...to automagically instantiate collections for me.
private IList<Foo> _foo;
public IList<Foo> ListOfFoo
{ get { return _foo ?? (_foo = new List<Foo>()); } }
share
...
iPhone: Detecting user inactivity/idle time since last screen touch
...f the screen receives a touch, the timer is reset.
override func sendEvent(_ event: UIEvent) {
super.sendEvent(event)
if idleTimer != nil {
self.resetIdleTimer()
}
if let touches = event.allTouches {
for touch in touches {
if touch.phase == UITouchPhase....
How to properly import a selfsigned certificate into Java keystore that is available to all Java app
...se: System.out.println(System.getProperty("java.home"));
Copy the file JAVA_HOME\lib\security\cacerts to another folder.
In Portecle click File > Open Keystore File
Select the cacerts file
Enter this password: changeit
Click Tools > Import Trusted Certificate
Browse for the file mycertificate....
Do AJAX requests retain PHP Session info?
If I had a user logged onto my site, having his id stored in $_SESSION , and from his browser he clicked a 'Save' button which would make an AJAX request to the server. Will his $_SESSION and cookies be retained in this request, and can I safely rely on the id being present in the $_SESSION ?
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How do you rename a MongoDB database?
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You could do this:
db.copyDatabase("db_to_rename","db_renamed","localhost")
use db_to_rename
db.dropDatabase();
Editorial Note: this is the same approach used in the question itself but has proven useful to others regardless.
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What is the difference between re.search and re.match?
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Now, enough talk. Time to see some example code:
# example code:
string_with_newlines = """something
someotherthing"""
import re
print re.match('some', string_with_newlines) # matches
print re.match('someother',
string_with_newlines) # won't match
print re.match('^someother', s...