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How to remove all null elements from a ArrayList or String Array?
... For Java 8 or later, see @MarcG's answer below.
– Andy Thomas
Feb 6 '16 at 15:16
2
@Hemanth Ca...
How to add images in select list?
...others</option>
</select>
Better yet, you can separate HTML and CSS like that
HTML
<select id="gender">
<option>male</option>
<option>female</option>
<option>others</option>
</select>
CSS
select#gender option[value="male"] ...
What is the equivalent of MATLAB's repmat in NumPy
... repmat(a, m, n) is tile(a, (m, n)).
This works with multiple dimensions and gives a similar result to matlab. (Numpy gives a 3d output array as you would expect - matlab for some reason gives 2d output - but the content is the same).
Matlab:
>> repmat([1;1],[1,1,1])
ans =
1
1
...
Why does C++ require a user-provided default constructor to default-construct a const object?
The C++ standard (section 8.5) says:
5 Answers
5
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Why JSF calls getters multiple times
... is caused by the nature of deferred expressions #{} (note that "legacy" standard expressions ${} behave exactly the same when Facelets is used instead of JSP). The deferred expression is not immediately evaluated, but created as a ValueExpression object and the getter method behind the expression i...
Python list subtraction operation
...set(x) - set(y))
>>> z
[0, 8, 2, 4, 6]
Or you might just have x and y be sets so you don't have to do any conversions.
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Computational complexity of Fibonacci Sequence
I understand Big-O notation, but I don't know how to calculate it for many functions. In particular, I've been trying to figure out the computational complexity of the naive version of the Fibonacci sequence:
...
When do you use Java's @Override annotation and why?
What are the best practices for using Java's @Override annotation and why?
27 Answers
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Aren't promises just callbacks?
I've been developing JavaScript for a few years and I don't understand the fuss about promises at all.
10 Answers
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ORA-00979 not a group by expression
...ults to a single value (like MIN, MAX or SUM).
A simple example to understand why this happens: Imagine you have a database like this:
FOO BAR
0 A
0 B
and you run SELECT * FROM table GROUP BY foo. This means the database must return a single row as result with the first column 0 to fulfill t...