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Android Get Current timestamp?
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From developers blog:
System.currentTimeMillis() is the standard "wall" clock (time and date) expressing milliseconds since the epoch. The wall clock can be set by the user or the phone network (see setCurrentTimeMillis(long)), so the time may jump backwards or forwards unpredictably. This c...
Get a random item from a JavaScript array [duplicate]
... not a valid substitution for Math.floor. Using round would cause accidentally referencing an undefined index, say in the case Math.random() is 0.95 and items.length is 5. Math.round(0.95*5) is 5, which would be an invalid index. floor(random) will always be zero in your example.
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What is the syntax rule for having trailing commas in tuple definitions?
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In all cases except the empty tuple the comma is the important thing. Parentheses are only required when required for other syntactic reasons: to distinguish a tuple from a set of function arguments, operator precedence, or to a...
Using “super” in C++
... the first time C++ was standardized.
Dag Bruck proposed this extension, calling the base class "inherited." The proposal mentioned the multiple inheritance issue, and would have flagged ambiguous uses. Even Stroustrup was convinced.
After discussion, Dag Bruck (yes, the same person making the p...
Invert “if” statement to reduce nesting
...cked this code from the refactoring catalog. This specific refactoring is called: Replace Nested Conditional with Guard Clauses.
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Access an arbitrary element in a dictionary in Python
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for a non-destructive popitem you can make a (shallow) copy: key, value = dict(d).popitem()
– Pelle
Jan 31 '18 at 10:35
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Convert a PHP object to an associative array
...e Typecasting with (array) and (object) works reliably and the same across all versions since PHP 4.3. See 3v4l.org/X6lhm. If you get a syntax error, you did something wrong.
– Gordon
Nov 30 '15 at 10:26
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Python: split a list based on a condition?
What's the best way, both aesthetically and from a performance perspective, to split a list of items into multiple lists based on a conditional? The equivalent of:
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Multiple constructors in python? [duplicate]
... Now you can do:
c = C(fd)
# or:
c = C.fromfilename('a filename')
Notice all those classmethods still go through the same __init__, but using classmethods can be much more convenient than having to remember what combinations of keyword arguments to __init__ work.
isinstance is best avoided becaus...
When to use in vs ref vs out
...ss you need ref.
It makes a big difference when the data needs to be marshalled e.g. to another process, which can be costly. So you want to avoid marshalling the initial value when the method doesn't make use of it.
Beyond that, it also shows the reader of the declaration or the call whether the ...