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How to test valid UUID/GUID?
... first character of the third block).
Therefore to validate a UUID...
/^[0-9a-f]{8}-[0-9a-f]{4}-[0-5][0-9a-f]{3}-[089ab][0-9a-f]{3}-[0-9a-f]{12}$/i
...ensures you have a canonically formatted UUID that is Version 1 through 5 and is the appropriate Variant as per RFC4122.
NOTE: Braces { and } ar...
Converting RGB to grayscale/intensity
...ic weights to channels R, G, and B ought to be applied. These weights are: 0.2989, 0.5870, 0.1140.
8 Answers
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Does the ternary operator exist in R?
...
306
As if is function in R and returns the latest evaluation, if-else is equivalent to ?:.
> a ...
How can I force division to be floating point? Division keeps rounding down to 0?
... I want to calculate a / b , so if I use integer division I'll always get 0 with a remainder of a .
11 Answers
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How to track down a “double free or corruption” error
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answered May 25 '10 at 8:42
HasturkunHasturkun
31.2k55 gold badges6565 silver badges9595 bronze badges
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Why do enum permissions often have 0, 1, 2, 4 values?
Why are people always using enum values like 0, 1, 2, 4, 8 and not 0, 1, 2, 3, 4 ?
7 Answers
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Grep characters before and after match?
... characters after
$> echo "some123_string_and_another" | grep -o -P '.{0,3}string.{0,4}'
23_string_and
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Using String Format to show decimal up to 2 places or simple integer
I have got a price field to display which sometimes can be either 100 or 100.99 or 100.9, What I want is to display the price in 2 decimal places only if the decimals are entered for that price , for instance if its 100 so it should only show 100 not 100.00 and if the price is 100.2 it should displa...
Reordering arrays
... would be:
Array.prototype.move = function (from, to) {
this.splice(to, 0, this.splice(from, 1)[0]);
};
Then just use:
var ar = [1,2,3,4,5];
ar.move(0,3);
alert(ar) // 2,3,4,1,5
Diagram:
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How to initialize a two-dimensional array in Python?
... \
for i in range (0, 10): \
new = [] \ can be replaced } this too
for j in range (0, 10): } with a list /
new.append(foo) / comprehension /
twod...