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Using mixins vs components for code reuse in Facebook React
...ycle methods (componentDidMount etc). This problem is solved by the Higher-Order Components that Dan Abramov talk in his link (or by using ES6 class inheritance).
Mixins are also often used in frameworks, to make framework API available to all the components, by using the "hidden" context feature o...
How do I delete a fixed number of rows with sorting in PostgreSQL?
...DELETE FROM logtable
WHERE ctid IN (
SELECT ctid
FROM logtable
ORDER BY timestamp
LIMIT 10
)
The ctid is:
The physical location of the row version within its table. Note that although the ctid can be used to locate the row version very quickly, a row's ctid will change if it is...
Using .sort with PyMongo
...er", 1), ("date", -1)])
The reason why this has to be a list is that the ordering of the arguments matters and dicts are not ordered in Python < 3.6
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What's the point of map in Haskell, when there is fmap?
... [b] -- Defined in ‘GHC.Base’
and you'll see it defined as an high-order function applicable to a list of values of any type a yielding a list of values of any type b. Although polymorphic (the a and b in the above definition stand for any type) the map function is intended to be applied to ...
Merge and interleave two arrays in Ruby
...
This won't give a result array in the order Chris asked for, but if the order of the resulting array doesn't matter, you can just use a |= b. If you don't want to mutate a, you can write a | b and assign the result to a variable.
See the set union documentation ...
GROUP BY with MAX(DATE) [duplicate]
...e FROM (
SELECT train, dest, time,
RANK() OVER (PARTITION BY train ORDER BY time DESC) dest_rank
FROM traintable
) where dest_rank = 1
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Use of 'const' for function parameters
... It’s like when the bad guy promises not to kill someone in a movie and orders his henchman to kill them instead.
Those superfluous const’s are worth no more than a promise from a movie bad-guy.
But the ability to lie gets even worse:
I have been enlightened that you can mismatch const in ...
Operator precedence with Javascript Ternary operator
...ach type of operator in a language is evaluated in a particular predefined order (and not just left-to-right).
Reference: Javascript Operator Precedence
How to change the order of evaluation:
Now we know why it fails, you need to know how to make it work.
Some other answers talk about changing t...
Why is there “data” and “newtype” in Haskell? [duplicate]
...e multiple value constructors (even
though CoolBool only has one). So in order to see if the value given
to our function conforms to the (CoolBool _) pattern, Haskell has to
evaluate the value just enough to see which value constructor was used
when we made the value. And when we try to eval...
Can you have multiple $(document).ready(function(){ … }); sections?
...'Hello Dexter!');
});
You'll find that it's equivalent to this, note the order of execution:
$(document).ready(function() {
alert('Hello Tom!');
alert('Hello Jeff!');
alert('Hello Dexter!');
});
It's also worth noting that a function defined within one $(document).ready block cannot...