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When is null or undefined used in JavaScript? [duplicate]
...nfused as to when JavaScript returns null or undefined . Also different browsers seem to be returning these differently.
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Force browser to download image files on click
I need the browser to download the image files just as it does while clicking on an Excel sheet.
14 Answers
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In-memory size of a Python structure
...here a reference for the memory size of Python data stucture on 32- and 64-bit platforms?
7 Answers
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Is Big O(logn) log base e?
For binary search tree type of data structures, I see the Big O notation is typically noted as O(logn). With a lowercase 'l' in log, does this imply log base e (n) as described by the natural logarithm? Sorry for the simple question but I've always had trouble distinguishing between the different...
How can I display an RTSP video stream in a web page?
...ides a live RTSP video stream. I can use VLC media player to view the feed by providing it with the URL:
15 Answers
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How to get JavaScript caller function line number? How to get JavaScript caller source URL?
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This works for me in chrome/QtWebView
function getErrorObject(){
try { throw Error('') } catch(err) { return err; }
}
var err = getErrorObject();
var caller_line = err.stack.split("\n")[4];
var index = caller_line.indexOf("at ");
var clean = caller_li...
Bash continuation lines
How do you use bash continuation lines?
11 Answers
11
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Getting back old copy paste behaviour in tmux, with mouse
This is what I used to do in tmux to copy-paste (using the mouse, the keyboard works differently and it is not what I am interested about):
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Simple way to calculate median with MySQL
... calculate the median with MySQL? I've used AVG(x) for finding the mean, but I'm having a hard time finding a simple way of calculating the median. For now, I'm returning all the rows to PHP, doing a sort, and then picking the middle row, but surely there must be some simple way of doing it in a s...
MySQL: Invalid use of group function
...s MySQL selects. Then MySQL groups the rows together and aggregates the numbers for your COUNT function.
HAVING is like WHERE, only it happens after the COUNT value has been computed, so it'll work as you expect. Rewrite your subquery as:
( -- where that pid is in the set:
SELECT ...