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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.
...
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 ...
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(...
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...
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...
delete a.x vs a.x = undefined
Is there any substantial difference in doing either of these?
9 Answers
9
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