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Why is String immutable in Java?
...le for several reasons, here is a summary:
Security: parameters are typically represented as String in network connections, database connection urls, usernames/passwords etc. If it were mutable, these parameters could be easily changed.
Synchronization and concurrency: making String immutable aut...
How to check if a variable is null or empty string or all whitespace in JavaScript?
I need to check to see if a variable is null or has all empty spaces or is just blank ("").
12 Answers
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Getting all names in an enum as a String[]
...<?>> e) {
return Arrays.toString(e.getEnumConstants()).replaceAll("^.|.$", "").split(", ");
}
That you would call like this:
String[] names = getNames(State.class); // any other enum class will work
If you just want something simple for a hard-coded enum class:
public static Strin...
Is recursion a feature in and of itself?
...int of learning a language, recursion isn't a feature. If your professor really docked you marks for using a "feature" he hadn't taught yet, that was wrong.
Reading between the lines, one possibility is that by using recursion, you avoided ever using a feature that was supposed to be a learning ou...
What's the difference between “Layers” and “Tiers”?
...on a single
computer or even in a single process
on a single computer. All we are doing
is discussing a way of organizing a
code into a set of layers defined by
specific function.
Physical tiers however, are only about
where the code runs. Specifically,
tiers are places where laye...
What are all the different ways to create an object in Java?
...
So actually only 2 ways exist: calling constructor (using new, clone() or reflection) and deserialization that does not invoke constructor.
– AlexR
Feb 24 '11 at 12:32
...
Pro JavaScript programmer interview questions (with answers) [closed]
What are good questions to determine if applicant is really a pro JavaScript (browser side) developer ?
8 Answers
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SQLiteDatabase.query method
...
tableColumns
null for all columns as in SELECT * FROM ...
new String[] { "column1", "column2", ... } for specific columns as in SELECT column1, column2 FROM ... - you can also put complex expressions here:
new String[] { "(SELECT max(column1) FROM...
Difference between maven scope compile and provided for JAR packaging
... scope, used if none is specified. Compile
dependencies are available in all classpaths of a project.
Furthermore, those dependencies are propagated to dependent projects.
provided
This is much like compile, but indicates you expect the JDK or a
container to provide the dependency at ru...
How to get number of rows using SqlDataReader in C#
...
There are only two options:
Find out by reading all rows (and then you might as well store them)
run a specialized SELECT COUNT(*) query beforehand.
Going twice through the DataReader loop is really expensive, you would have to re-execute the query.
And (thanks to Pete ...