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What is the difference between List (of T) and Collection(of T)?
...s that it is returning a new instance. Note that for e.g. a Dictionary<string, List<string>> to return List<string> is just fine, since the dictionary's state only encapsulates the identities of the lists therein, rather than their contents.
– supercat
...
Deleting all files in a directory with Python
... list of file names which end it '.bak'. The elements of the list are just strings.
Then you could use os.unlink to remove the files. (PS. os.unlink and os.remove are synonyms for the same function.)
#!/usr/bin/env python
import glob
import os
directory='/path/to/dir'
os.chdir(directory)
files=glo...
Why are const parameters not allowed in C#?
...od type system, a type system where when you say "this variable contains a string" that the variable actually contains a reference to a string (or null). We absolutely do not want to put a C-style "const" modifier into the type system because we don't want the type system to be a lie. We want the ty...
Flexbox Not Centering Vertically in IE
... 2019, the best solution by far is the one by @sergey-fedirko requiring no extra HTML elements and no hard heights ;) This one: stackoverflow.com/a/54796082/134120
– AsGoodAsItGets
Mar 12 '19 at 12:19
...
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...' the matrix.
#'
#' @param data data.frame: input data
#' @param rowtitle string: row-dimension; name of the column in data, which distinct values should be used as row names in the output matrix
#' @param coltitle string: col-dimension; name of the column in data, which distinct values should be u...
Difference between single and double square brackets in Bash
...nsion.
expr a \< b > /dev/null: POSIX equivalent², see: How to test strings for lexicographic less than or equal in Bash?
&& and ||
[[ a = a && b = b ]]: true, logical and
[ a = a && b = b ]: syntax error, && parsed as an AND command separator cmd1 &&...
Collections.emptyMap() vs new HashMap()
...e this, and does not allow null references:
public ResultSet executeQuery(String query, Map<String, Object> queryParameters);
If you have a query that doesn't take any parameters, it's certainly a bit wasteful to create a HashMap, which involves allocating an array, when you could just pass...
The entitlements specified…profile. (0xE8008016). Error iOS 4.2
... run the HealthKit "fit" app for iOS8 - there was an additional identifier string in the entitlements file. Removing it allowed the project to run after following other steps mentioned in this thread
– Alex Stone
Jul 17 '14 at 18:38
...
Installing Ruby Gem in Windows
...uby 2.0.0p353 (2013-11-22) [i386-mingw32]
For Ruby 2.4 or later, run the extra installation at the end to install the DevelopmentKit. If you forgot to do that, run ridk install in your windows console to install it.
For earlier versions:
Download and install DevelopmentKit from the same downloa...
Is it possible for a computer to “learn” a regular expression by user-provided examples?
...
Yes, it's certainly "possible"; Here's the pseudo-code:
string MakeRegexFromExamples(<listOfPosExamples>, <listOfNegExamples>)
{
if HasIntersection(<listOfPosExamples>, <listOfNegExamples>)
return <IntersectionError>
string regex = "";
...