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Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]
...t, I'll use [ ! "$var" ] instead of [ -z "$var" ].
– AllenHalsey
Oct 6 '10 at 20:32
2
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ViewParam vs @ManagedProperty(value = “#{param.id}”)
...alues. Since JSF 2.2 you could use <f:viewAction> for that instead.
Allows for nested <f:converter> and <f:validator> for more fine-grained conversion/validation. Even a <h:message> can be attached.
Can be included as GET query string using includeViewParams attribute of &l...
Matplotlib (pyplot) savefig outputs blank image
...values that depend whether or not T0 exists.
Second, after plt.show() is called, a new figure is created. To deal with this, you can
Call plt.savefig('tessstttyyy.png', dpi=100) before you call plt.show()
Save the figure before you show() by calling plt.gcf() for "get current figure", then you ca...
What is the purpose of the “final” keyword in C++11 for functions?
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@AaronMcDaid: Compilers usually warn about code that, being correct, might cause confusion or errors. I have never seen anyone surprised by this particular feature of the language in a way that could cause any problem, so I don't really know how useful...
Android TextWatcher.afterTextChanged vs TextWatcher.onTextChanged
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These events are called in the following order:
beforeTextChanged(CharSequence s, int start, int count, int after).
This means that the characters are about to be replaced with some new text. The text is uneditable.
Use: when you need to tak...
Plot smooth line with PyPlot
...) (Plus there's no harm in making the coments a bit more PEP8 style, after all it's "exposed code".) But in general: thanks for the example!
– brezniczky
Oct 25 '19 at 15:02
1
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Animate scroll to ID on page load
...into view on page load, but had two issues: a) using "html,body" gave two callbacks (one for each matched element). b) It depends on browser which of body or html works. So I made a gist which you can adapt to use in your project to ensure scroll-into-view works on "any" browser and that you will on...
Why Collections.sort uses merge sort instead of quicksort?
...to provide a stable sort (Merge Sort)
to sort object references. (Techincally speaking, multiple sequential
stable sorts result in a lexicographic ordering on the keys in the
reverse order of the sorts: the final sort determines the most
significant subkey.)
It's a nice side benefit tha...
Rails “validates_uniqueness_of” Case Sensitivity
... 3rd Edition:
...despite its name, validates_uniqueness_of doesn’t really guarantee that column values will be unique. All it can do is verify that no column has the same value as that in the record being validated at the time the validation is performed. It’s possible for two records to be ...
Difference between Document-based and Key/Value-based databases?
...e debate on the correct name for databases such as Cassandra, I'd like to call them column-family stores. Although key-value pairs are an essential part of Cassandra, it's not limited to just that. It allows you to nest key-value pairs, so a key could refer to multiple sub-key-value pairs.
You cann...