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Best way to create an empty map in Java
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You'll have to use the latter sometimes when the compiler cannot automatically figure out what kind of Map is needed (this is called type inference). For example, consider a method declared like this:
public void foobar(Map<String, String> map){ ... }
When passing the empty Map direc...
“unrecognized selector sent to instance” error in Objective-C
...I was getting the error because I forgot to put a colon after the selector callback, thus causing a calling sequence mismatch. With the colon, I can keep the sender argument.
– user1886876
May 20 '13 at 22:34
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How to insert values into C# Dictionary on instantiation?
...gt;()
{
{ 111, new StudentName {FirstName="Sachin", LastName="Karnik", ID=211}},
{ 112, new StudentName {FirstName="Dina", LastName="Salimzianova", ID=317}},
{ 113, new StudentName {FirstName="Andy", LastName="Ruth", ID=198}}
};
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Can I have multiple primary keys in a single table?
...made from two or more columns. For example:
CREATE TABLE userdata (
userid INT,
userdataid INT,
info char(200),
primary key (userid, userdataid)
);
Update: Here is a link with a more detailed description of composite primary keys.
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HashMap with multiple values under the same key
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No, not just as a HashMap. You'd basically need a HashMap from a key to a collection of values.
If you're happy to use external libraries, Guava has exactly this concept in Multimap with implementations such as ArrayListMultimap and HashMultimap.
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How to get the home directory in Python?
...re working with pathlib, you may prefer the pathlib solution (and omit the call of str). If you just want the path as string, they both do the same.
– Niklas Mertsch
Aug 15 '19 at 12:31
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How do you implement a private setter when using an interface?
...o not part of interface
Setter is not part of interface, so it cannot be called via your interface:
IBar bar = new Bar();
bar.Foo = 42; // will not work thus setter is not defined in interface
bar.Poop(); // will not work thus Poop is not defined in interface
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SQL Server: Examples of PIVOTing String data
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If you specifically want to use the SQL Server PIVOT function, then this should work, assuming your two original columns are called act and cmd. (Not that pretty to look at though.)
SELECT act AS 'Action', [View] as 'View', [Edit] as 'Edi...
How do I turn a String into a InputStreamReader in java?
...ing? I think as long as you pick the same encoding for the String#getBytes call as you pick for the InputSTreamReader constructor, it doesn't really matter which one you pick. I am pretty sure that Joachim and McDowell are wrong for this specific case. No encoding knowledge needed for wrapping an In...
In which order do CSS stylesheets override?
...REC-CSS2-20110607/cascade.html#cascade
In short: more specific rules override more general ones. Specificity is defined based on how many IDs, classes, and element names are involved, as well as whether the !important declaration was used. When multiple rules of the same "specificity level" exist, ...