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What is the difference between ArrayList.clear() and ArrayList.removeAll()?
Assuming that arraylist is defined as ArrayList<String> arraylist , is arraylist.removeAll(arraylist) equivalent to arraylist.clear() ?
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Using Java 8's Optional with Stream::flatMap
...de() {
return optional.hashCode();
}
@Override
public String toString() {
return optional.toString();
}
}
You will see that I added flatStream(), as here:
public Stream<T> flatStream() {
if (!optional.isPresent()) {
return Stream.empty();
}
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Copy a table from one database to another in Postgres
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Extract the table and pipe it directly to the target database:
pg_dump -t table_to_copy source_db | psql target_db
Note: If the other database already has the table set up, you should use the -a flag to import data only, else you may see we...
What is the motivation for bringing Symbols to ES6?
...t that the :symbol notion in Ruby is needless; we could easily use plain strings instead, like we do in JavaScript. And now they decide to complicate things in JS with that.
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How long is the SHA256 hash?
...256', 'hello, world!');
var_dump($hash);
Will give you :
$ php temp.php
string(64) "68e656b251e67e8358bef8483ab0d51c6619f3e7a1a9f0e75838d41ff368f728"
i.e. a string with 64 characters.
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How to let PHP to create subdomain automatically for each user?
...p though because you'll have to make sure that all subdomain requests get handled properly. This isn't terrible with Apache but might be tricky in a hosted environment.
– Mark Biek
Oct 8 '08 at 17:55
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Python time measure function
... return wrap
Note I'm calling f.func_name to get the function name as a string(in Python 2), or f.__name__ in Python 3.
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What are the differences between JSON and JSONP?
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JSONP is JSON with padding. That is, you put a string at the beginning and a pair of parentheses around it. For example:
//JSON
{"name":"stackoverflow","id":5}
//JSONP
func({"name":"stackoverflow","id":5});
The result is that you can load the JSON as a script file. If ...
Best practice? - Array/Dictionary as a Core Data Entity Attribute [closed]
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I had a similar issue. In my case, I wanted to map an array of strings. I followed Barry's advice and finally got it working. Here is what some of the code looks like (which will hopefully clarify things for anyone else who runs into this)...
My Entity looks something like this:
@int...
How to add an extra column to a NumPy array
...this is a better answer than the accepted one, because it covers adding an extra column at the beginning and at the end, not just at the end as the other answers
– Ay0
Jul 23 '15 at 11:02
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