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Get the first key name of a javascript object [duplicate]
..." key in a hash (Javascript calls them objects). They are fundamentally unordered. Do you mean just choose any single key:
for (var k in ahash) {
break
}
// k is a key in ahash.
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Cookies vs. sessions
...
Short answer
Rules ordered by priority:
Rule 1. Never trust user input : cookies are not safe. Use sessions for sensitive data.
Rule 2. If persistent data must remain when the user closes the browser, use cookies.
Rule 3. If persistent data d...
Can you have if-then-else logic in SQL? [duplicate]
... in dbs it is not optimal because this syntax is procedural - it would be orders of magnitude slower than a proper set based query.
– mson
Feb 28 '13 at 13:42
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My Understanding of HTTP Polling, Long Polling, HTTP Streaming and WebSockets
..., long poll, streaming.
Bi-direcitonal: WebSockets, plugin networking
In order of increasing latency (approximate):
WebSockets
Plugin networking
HTTP streaming
HTTP long-poll
HTTP polling
CORS (cross-origin support):
WebSockets: yes
Plugin networking: Flash via policy request (not sure about...
403 Forbidden vs 401 Unauthorized HTTP responses
... (or 3xx: redirection)
Checks are usually done in this order:
404 if resource is public and does not exist or 3xx redirection
OTHERWISE:
401 if not logged-in or session expired
403 if user does not have permission to access resource (file, json, ...)
404 if resource does not ex...
Can you control how an SVG's stroke-width is drawn?
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You can use CSS to style the order of stroke and fills. That is, stroke first and then fill second, and get the desired effect.
MDN on paint-order: https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/paint-order
CSS code:
paint-order: stroke;
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Git cherry pick vs rebase
...nto it.
Tries to apply each of the saved commits (as if with git apply) in order. In our toy example it's just one commit, C3. Let's say its application will produce a commit C3'.
If all went well, the "experiment" reference is updated to point to the commit resulted from applying the last saved com...
must appear in the GROUP BY clause or be used in an aggregate function
...ax:
SELECT DISTINCT ON (cname)
cname, wmname, avg
FROM
makerar
ORDER BY
cname, avg DESC ;
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Performance of Arrays vs. Lists
...ing the Capacity of the list to the number of items it will hold.
But, in order to figure out if iterating over a List is as fast as iterating over an array, why don't you benchmark it ?
int numberOfElements = 6000000;
List<int> theList = new List<int> (numberOfElements);
int[] theAr...
Efficient paging in SQLite with millions of records
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Please note that you always have to use an ORDER BY clause; otherwise, the order is arbitrary.
To do efficient paging, save the first/last displayed values of the ordered field(s), and continue just after them when displaying the next page:
SELECT *
FROM MyTable
WHE...