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Handling warning for possible multiple enumeration of IEnumerable
...y to this method, only for you to enumerate it twice (getting potentially different results each time?)
The semantic missing here is that a caller, who perhaps doesn't take time to read the details of the method, may assume you only iterate once - so they pass you an expensive object. Your method s...
Filter dict to contain only certain keys?
...t[your_key] for your_key in your_keys }
Uses dictionary comprehension.
If you use a version which lacks them (ie Python 2.6 and earlier), make it dict((your_key, old_dict[your_key]) for ...). It's the same, though uglier.
Note that this, unlike jnnnnn's version, has stable performance (depends ...
Checking if a list is empty with LINQ
...e "best" (taking both speed and readability into account) way to determine if a list is empty? Even if the list is of type IEnumerable<T> and doesn't have a Count property.
...
How to convert C# nullable int to int
... v1 == null ? default(int) : v1;
...which is in turn syntax sugar for an if/else:
if(v1==null)
v2 = default(int);
else
v2 = v1;
Also, as of .NET 4.0, Nullable<T> has a "GetValueOrDefault()" method, which is a null-safe getter that basically performs the null-coalescing shown above...
How to mkdir only if a directory does not already exist?
...dir -p foo/bar/baz
will create directories foo, foo/bar, and foo/bar/baz if they don't exist.
Some implementation like GNU mkdir include mkdir --parents as a more readable alias, but this is not specified in POSIX/Single Unix Specification and not available on many common platforms like macOS, va...
Use of Finalize/Dispose method in C#
...);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
// get rid of managed resources
}
// get rid of unmanaged resources
}
// only if you use unmanaged resources directly in B
//~B()
//{
// Dispose(...
Linq code to select one item
...methods directly like:
var item = Items.First(i => i.Id == 123);
And if you don't want to throw an error if the list is empty, use FirstOrDefault which returns the default value for the element type (null for reference types):
var item = Items.FirstOrDefault(i => i.Id == 123);
if (item !=...
How to compare arrays in C#? [duplicate]
... Great answer, and I know it's a little late, but that could be simplified to this: bool isEqual = target1.SequenceEqual(target2);
– Connie Hilarides
Mar 16 '14 at 7:57
...
Test whether a glob has any matches in bash
If I want to check for the existence of a single file, I can test for it using test -e filename or [ -e filename ] .
19 ...
How to get the ActionBar height?
...
While @birdy's answer is an option if you want to explicitly control the ActionBar size, there is a way to pull it up without locking the size that I found in support documentation. It's a little awkward but it's worked for me. You'll need a context, this ex...