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What's the point of 'const' in the Haskell Prelude?
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Say you want to create a list of Nothings equal to the length of a string. As const returns its first argument, no matter the second, you can do:
listOfNothings :: String -> [Maybe Char]
listOfNothings = (map . const) Nothing
or, more explicitly:
listOfNothing st = map (const Nothing)...
Easiest way to read from and write to files
...and File.WriteAllText.
MSDN example excerpt:
// Create a file to write to.
string createText = "Hello and Welcome" + Environment.NewLine;
File.WriteAllText(path, createText);
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// Open the file to read from.
string readText = File.ReadAllText(path);
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Android emulator and virtualbox cannot run at same time
...version of Intel Emulator Accelerator HAXM installed (v6.1.1) .
Go to the extras directory of the Android SDK location displayed in the preferences. On MacOS you can do this:
open ~/Library/Android/sdk/extras
Install the HAXM packing by opening IntelHAXM_6.1.1.dmg, then opening IntelHAXM_6.1.1.mpk...
Delete empty lines using sed
...y here means, the line contains no chars, or the line contains only empty strings (E.g. spaces). All matched lines will be removed by sed, with the d command.
– Kent
Feb 26 '17 at 19:41
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How to do ToString for a possibly null object?
...# 6.0 we can now have a succinct, cast-free version of the orignal method:
string s = myObj?.ToString() ?? "";
Or even using interpolation:
string s = $"{myObj}";
Original Answer:
string s = (myObj ?? String.Empty).ToString();
or
string s = (myObjc ?? "").ToString()
to be even more concise.
Unfo...
Using Enum values as String literals
What is the best way to use the values stored in an Enum as String literals?
For example:
18 Answers
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Why is \r a newline for Vim?
...tches <CR>
\n matches an end-of-line -
When matching in a string instead of
buffer text a literal newline
character is matched.
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How to put a new line into a wpf TextBlock control?
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baz bar</data>
If that does not work you might need to parse the string manually.
If you need direct XAML that's easy by the way:
<TextBlock>
Lorem <LineBreak/>
Ipsum
</TextBlock>
share...
Specifying a custom DateTime format when serializing with Json.Net
...y ARE correct, although they are not strictly necessary here. See Literal String Delimiters in the documentation for Custom Date and Time Format Strings. However, the format I quoted as the default format for the IsonDateTimeConverter was taken directly from the Json.Net source code; therefore I a...
How do I create a comma-separated list from an array in PHP?
...r if you want to manipulate that data in the array before making it into a string; For example, addslashes, or mysql_real_escape_string.
– Naphtali Gilead
Aug 21 '15 at 15:48
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