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Is there a standard function to check for null, undefined, or blank variables in JavaScript?
...l evaluate to true if value is not:
null
undefined
NaN
empty string ("")
0
false
The above list represents all possible falsy values in ECMA-/Javascript. Find it in the specification at the ToBoolean section.
Furthermore, if you do not know whether a variable exists (that means, if it was decla...
Peak detection in a 2D array
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+500
I detected the peaks using a local maximum filter. Here is the result on your first dataset of 4 paws:
I also ran it on the second ...
Unique random string generation
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answered Apr 8 '09 at 14:58
Mark SynowiecMark Synowiec
4,9371919 silver badges1818 bronze badges
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JUnit: how to avoid “no runnable methods” in test utils classes
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10 Answers
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Listing all permutations of a string/integer
...more elaborate (and since it is tagged c #), from http://radio.weblogs.com/0111551/stories/2002/10/14/permutations.html :
Rather lengthy, but I decided to copy it anyway, so the post is not dependent on the original.
The function takes a string of characters, and writes down every possible permutat...
Are std::vector elements guaranteed to be contiguous?
... C++98 standard proper but later added as part of a TR. The forthcoming C++0x standard will of course contain this as a requirement.
From n2798 (draft of C++0x):
23.2.6 Class template vector [vector]
1 A vector is a sequence container that supports random access iterators. In addition, it ...
Python time measure function
...et = f(*args)
time2 = time.time()
print '%s function took %0.3f ms' % (f.func_name, (time2-time1)*1000.0)
return ret
return wrap
And the usage is very simple, just use the @timing decorator:
@timing
def do_work():
#code
Python 3:
def timing(f):
def wrap(*args, **k...
Fastest way to tell if two files have the same contents in Unix/Linux?
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410
I believe cmp will stop at the first byte difference:
cmp --silent $old $new || echo "files are...
JavaScript URL Decode function
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220
I've used encodeURIComponent() and decodeURIComponent() too.
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Input placeholders for Internet Explorer
...Length="6" type="text" placeholder="Hi Mom">
<label style="font: 0.75em/normal sans-serif; left: 5px; top: 3px; width: 147px; height: 15px; color: rgb(186, 186, 186); position: absolute; overflow-x: hidden; font-size-adjust: none; font-stretch: normal;" for="placeholder1314588474481">Hi...