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What is the difference between ArrayList.clear() and ArrayList.removeAll()?
...h faster since it doesn't have to deal with all those extra method calls.
And as Atrey points out, c.contains(..) increases the time complexity of removeAll to O(n2) as opposed to clear's O(n).
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How do I format date and time on ssrs report?
on SSRS report I need to show todays date and current time
12 Answers
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Java Class that implements Map and keeps insertion order?
...or most cases; TreeMap has O(log n) performance for containsKey, get, put, and remove, according to the Javadocs, while LinkedHashMap is O(1) for each.
If your API that only expects a predictable sort order, as opposed to a specific sort order, consider using the interfaces these two classes implem...
What does @media screen and (max-width: 1024px) mean in CSS?
... as opposed to e.g. an older mobile phone browser (note that the iPhone, and other smartphone browsers, do identify themselves as being in the screen category), or a screenreader — and that it’s displaying the page on-screen, rather than printing it.
max-width: 1024px — the width of the browse...
delegate keyword vs. lambda notation
...delegates (such as System.Func) uses System.Linq.Enumerable. Linq to SQL (and anything else) with expressions uses System.Linq.Queryable. Check out the parameters on those methods.
An Explanation from ScottGu. In a nutshell, Linq in-memory will produce some anonymous methods to resolve your query...
Why does HTML think “chucknorris” is a color?
How come certain random strings produce colors when entered as background colors in HTML? For example:
9 Answers
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Get list of databases from SQL Server
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To expand on what @ChrisDiver said: SELECT name FROM sys.databases is the preferred approach now, rather than dbo.sysdatabases, which has been deprecated for a decade now.
– Micah
Feb 3 '16 a...
Version number comparison in Python
I want to write a cmp -like function which compares two version numbers and returns -1 , 0 , or 1 based on their compared valuses.
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compareTo() vs. equals()
...) . This feels unnatural (as compareTo() is meant to provide an ordering and not compare for equality) and even somewhat dangerous (because compareTo() == 0 does not necessarily imply equality in all cases, even though I know it does for String 's) to me.
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In Perl, how can I read an entire file into a string?
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Add:
local $/;
before reading from the file handle. See How can I read in an entire file all at once?, or
$ perldoc -q "entire file"
See Variables related to filehandles in perldoc perlvar and perldoc -f local.
Incidentally, if you can put your script on the server,...