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JavaScript checking for null vs. undefined and difference between == and ===
...hey're falsey:
if (!a) {
// `a` is falsey, which includes `undefined` and `null`
// (and `""`, and `0`, and `NaN`, and [of course] `false`)
}
This is defined by ToBoolean in the spec.
...and what is the difference between the null and undefined?
They're both values usually used to i...
Convert tuple to list and back
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@Jimmy that's because list is a debugger command, run p list(...) instead.
– moritz
Jan 24 '19 at 2:26
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How do I declare and initialize an array in Java?
How do I declare and initialize an array in Java?
28 Answers
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Unicode equivalents for \w and \b in Java regular expressions?
Many modern regex implementations interpret the \w character class shorthand as "any letter, digit, or connecting punctuation" (usually: underscore). That way, a regex like \w+ matches words like hello , élève , GOÄ_432 or gefräßig .
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How can I match a string with a regex in Bash?
...is not a concern, I recommend using [[ instead of [ or test as it is safer and more powerful. See What is the difference between test, [ and [[ ? for details.
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Git for beginners: The definitive practical guide
...k, after seeing this post by PJ Hyett , I have decided to skip to the end and go with Git .
37 Answers
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Comparing numbers in Bash
...hen
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fi
For POSIX shells that don't support (()), you can use -lt and -gt.
if [ "$a" -gt "$b" ]; then
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fi
You can get a full list of comparison operators with help test or man test.
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Javascript and regex: split string and keep the separator
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I don't understand why everybody is using /g
– Sarsaparilla
Jan 11 '17 at 18:22
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OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection
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This is a recurring subject in Stackoverflow and since I was unable to find a relevant implementation I decided to accept the challenge.
I made some modifications to the squares demo present in OpenCV and the resulting C++ code below is able to detect a sheet of paper ...
Is R's apply family more than syntactic sugar?
...regarding execution time and / or memory.
5 Answers
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