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Appending an element to the end of a list in Scala
...lts in List[Int] = List(1, 2, 3, 4)
Note that this operation has a complexity of O(n). If you need this operation frequently, or for long lists, consider using another data type (e.g. a ListBuffer).
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Parse a .py file, read the AST, modify it, then write back the modified source code
...cally generates as does the 2to3 tool for python 2.6 (it converts python 2.x source into python 3.x source).
Both these tools uses the lib2to3 library which is a implementation of the python parser/compiler machinery that can preserve comments in source when it's round tripped from source -> AS...
How to convert a string from uppercase to lowercase in Bash? [duplicate]
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If you are using bash 4 you can use the following approach:
x="HELLO"
echo $x # HELLO
y=${x,,}
echo $y # hello
z=${y^^}
echo $z # HELLO
Use only one , or ^ to make the first letter lowercase or uppercase.
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Purpose of returning by const value? [duplicate]
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In the hypothetical situation where you could perform a potentially expensive non-const operation on an object, returning by const-value prevents you from accidentally calling this operation on a temporary. Imagine that + returned a non-const value, and you could write:
(a + b).expensive();
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Convert a list of objects to an array of one of the object's properties
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You are looking for
MyList.Select(x=>x.Name).ToArray();
Since Select is an Extension method make sure to add that namespace by adding a
using System.Linq
to your file - then it will show up with Intellisense.
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Overloading member access operators ->, .*
I understand most operator overloading, with the exception of the member access operators -> , .* , ->* etc.
5 An...
How to display a dynamically allocated array in the Visual Studio debugger?
... will only display the first element of the array when you click the + to expand it. Is there an easy way to tell the debugger, show me this data as an array of type Foo and size X?
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Performance differences between debug and release builds
...d code so difficult. And giving the volatile keyword a meaning.
Array index checking elimination. An important optimization when working with arrays (all .NET collection classes use an array internally). When the JIT compiler can verify that a loop never indexes an array out of bounds then it wil...
Retrieve database or any other file from the Internal Storage using run-as
...atabases/file from an Android 5.1+ device run the following command:
adb exec-out run-as debuggable.app.package.name cat databases/file > file
To download multiple files in a folder under the /data/data/debuggable.app.package.name/ at once - use tar:
adb exec-out run-as debuggable.app.package...
Inserting string at position x of another string
...al: As a prototype method of String
The following can be used to splice text within another string at a desired index, with an optional removeCount parameter.
if (String.prototype.splice === undefined) {
/**
* Splices text within a string.
* @param {int} offset The position to inser...