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Test if a variable is set in bash when using “set -o nounset”
... want to check only whether it's unset, use -: VALUE=${WHATEVER-}. Also, a more readable way to check whether a variable is empty: if [ "${WHATEVER+defined}" = defined ]; then echo defined; else echo undefined; fi
– l0b0
Oct 24 '11 at 11:04
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correct way to define class variables in Python [duplicate]
...ents of the object (self); they don't belong to the class.
You'll see it more clearly with some code:
class MyClass:
static_elem = 123
def __init__(self):
self.object_elem = 456
c1 = MyClass()
c2 = MyClass()
# Initial values of both elements
>>> print c1.static_elem, c...
Add CSS or JavaScript files to layout head from views or partial views
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Is there any Rails function to check if a partial exists?
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How to justify a single flexbox item (override justify-content)
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After some more investigation, justify-self might not have anything to do with flexbox but rather is used with css grids but I'm not sure. I can't seem to get it to work in Chrome with flexbox.
– Jake Wilson
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How to use a variable for a key in a JavaScript object literal?
... @AndyE consider updating "recent versions" and "current IE TP" with some more specific time like "Versions later than XXX" or "after 2014-mm" (I'd make change myself, but I don't know what good values would be.
– Alexei Levenkov
Feb 26 '15 at 1:59
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Different types of thread-safe Sets in Java
... avoid this by estimating the needed size on creation (and using about 1/3 more of that, as it resizes when 3/4 full).
Use this when you have large sets, a good (and fast) hash function and can estimate the set size and needed concurrency before creating the map.
5) Are there other concurrent map ...
How to check if a string is a valid hex color representation?
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Where to put include statements, header or source?
...rogrammers still follow this model (religiously, in at least some cases).
More recently, there's a movement toward making most headers standalone. If that header requires something else, the header itself handles that, ensuring that whatever it needs is included (in the correct order, if there are ...
How do I insert a linebreak where the cursor is without entering into insert mode in Vim?
...'g' with any character that's not already linked to a command you use.
Add more to the command, e.g. f}i^M^[O -- This will find the } and insert another newline, then escape from insert mode and Open an empty line for you to enter more code.
You can add the command to your .vimrc or .exrc file to m...