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Regex to check whether a string contains only numbers [duplicate]
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If you want to test if a string is a parse-able number, including negatives and decimal: /^-?\d+\.?\d*$|^\d*\.?\d+$/
– SpYk3HH
Apr 5 '16 at 18:59
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How to append something to an array?
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Some quick benchmarking (each test = 500k appended elements and the results are averages of multiple runs) showed the following:
Firefox 3.6 (Mac):
Small arrays: arr[arr.length] = b is faster (300ms vs. 800ms)
Large arrays: arr.push(b) is faster (500ms...
How to fallback to local stylesheet (not script) if CDN fails
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Not cross-browser tested but I think this will work. Will have to be after you load jquery though, or you'll have to rewrite it in plain Javascript.
<script type="text/javascript">
$.each(document.styleSheets, function(i,sheet){
if(s...
How to determine when a Git branch was created?
...ich will show you branch events clearly:
git reflog --date=local --all
860e4e4 refs/heads/master@{Sun Sep 19 23:00:30 2010}: commit: Second.
17695bc refs/heads/example_branch@{Mon Sep 20 00:31:06 2010}: branch: Created from HEAD
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How do I view all commits for a specific day?
...-03 13:37:16 -0700
Last commit: 1d4c88c 1d4c88ce6a15efaceda1d653eed3346fcae8f5e6 2018-10-13 21:32:27 -0700
Date to search for commits: 2015-08-13
Date to search for commits: 2015-08-03
375bcfb 375bcfbbf548134a4e34c36e3f28d87c53b2445f Mike Slinn 2015-08-03 13:37:16 -0700 'this is a comment'
Date t...
Best introduction to C++ template metaprogramming? [closed]
... community wiki
12 revs, 2 users 92%jwfearn
2
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How do I check out a remote Git branch?
Somebody pushed a branch called test with git push origin test to a shared repository. I can see the branch with git branch -r .
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Remove NA values from a vector
...ively slower (though I'll happily take comments on my implementation & test!)
microbenchmark::microbenchmark(
purrr::map(airquality,function(x) {x[!is.na(x)]}),
purrr::map(airquality,na.omit),
purrr::map(airquality, ~purrr::discard(.x, .p = is.na)),
times = 1e6)
Unit: microseconds
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What is the volatile keyword useful for?
... volatile variable to control whether some code continues a loop. The loop tests the volatile value and continues if it is true. The condition can be set to false by calling a "stop" method. The loop sees false and terminates when it tests the value after the stop method completes execution.
The bo...
How to make a great R reproducible example
...he original ones. (eg op <- par(mfrow=c(1,2)) ...some code... par(op) )
test run your code in a new, empty R session to make sure the code is runnable. People should be able to just copy-paste your data and your code in the console and get exactly the same as you have.
Give extra information
I...