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(Built-in) way in JavaScript to check if a string is a valid number
...ter-intuitive. +num converts empty strings or strings with spaces to zero, and isNaN() assumes the same:
+'' // 0
+' ' // 0
isNaN('') // false
isNaN(' ') // false
But parseInt() does not agree:
parseInt('') // NaN
parseInt(' ') // NaN
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Fastest way to determine if record exists
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@Declan_K: seems like my magic sphere failed in this case and a column entitled as id isn't PK. So +1 to your advice.
– zerkms
Aug 7 '13 at 22:00
4
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Question mark (?) in XML attributes for Android
Can anyone explain the question mark means in Android XML attributes?
2 Answers
2
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Is optimisation level -O3 dangerous in g++?
...mpiling with an optimisation level of -O3 in g++ is somehow 'dangerous', and should be avoided in general unless proven to be necessary.
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How do I protect Python code? [closed]
...se a exe-packager like py2exe, the layout of the executable is well-known, and the Python byte-codes are well understood.
Usually in cases like this, you have to make a tradeoff. How important is it really to protect the code? Are there real secrets in there (such as a key for symmetric encryptio...
How to index into a dictionary?
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Dictionaries are unordered in Python versions up to and including Python 3.6. If you do not care about the order of the entries and want to access the keys or values by index anyway, you can use d.keys()[i] and d.values()[i] or d.items()[i]. (Note that these methods create a...
What is the difference between a generative and a discriminative algorithm?
Please, help me understand the difference between a generative and a
discriminative algorithm, keeping in mind that I am just a beginner.
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How do I find the duplicates in a list and create another list with them?
How can I find the duplicates in a Python list and create another list of the duplicates? The list only contains integers.
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What exactly is metaprogramming?
... eval("x" + i). DoSomething() would affect an object called x1 when i is 1 and x2 when i is 2.
Finally, another common form of metaprogramming is when the program can change itself in non-trivial fashions. LISP is well known for this and is something Paul Graham championed about a decade ago. I'll ...
'git' is not recognized as an internal or external command
...ve an installation of Git for Windows, but when I try to use the git command in Command Prompt, I get the following error:
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