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Disable cache for some images
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Instead of random numbers, use the timestamp that the data changed or a version number of the reflected data.
– lhunath
Apr 8 '09 at 19:00
4...
Picking a random element from a set
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if your data is in a hash set, you need O(n) time. There's no way around it if you are just picking a single element and the data is stored in a HashSet.
– David Nehme
Sep 25 '08 at 2:00
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Does every web request send the browser cookies?
..., if the cookie's host, path, etc. restrictions are met, it'll be sent, 50 times.
But you also asked why: because cookies are an HTTP feature, and HTTP is stateless. HTTP is designed to work without the server storing any state between requests.
In fact, the server doesn't have a solid way of reco...
Difference between fold and reduce?
Trying to learn F# but got confused when trying to distinguish between fold and reduce . Fold seems to do the same thing but takes an extra parameter. Is there a legitimate reason for these two functions to exist or they are there to accommodate people with different backgrounds? (E.g.: String ...
Run javascript function when user finishes typing instead of on key up?
...inished typing in a text box. I don't want it to run the function on every time the user types a letter because that would result in A LOT of ajax requests, however I don't want them to have to hit the enter button either.
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What is the difference between jQuery: text() and html() ?
...unction jQuery adds an "entity filter", and this filter naturally consumes time.
Ok, if you really want performance... Use pure Javascript to access direct text-replace by the nodeValue property.
Benchmark conclusions:
jQuery's .html() is ~2x faster than .text().
pure JS' .innerHTML is ~3x faster ...
jQuery textbox change event doesn't fire until textbox loses focus?
...lue = $(this).val();
console.log('The text box really changed this time');
}
});
And if you want to be super duper pedantic then you should use an interval timer to cater for auto fill, plugins, etc:
var lastValue = '';
setInterval(function() {
if ($("#textbox").val() != lastValue...
Check if a program exists from a Makefile
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Sometimes you need a Makefile to be able to run on different target OS's and you want the build to fail early if a required executable is not in PATH rather than to run for a possibly long time before failing.
The excellent solu...
How to assign the output of a command to a Makefile variable
...ion is mildly old, it's best to do MY_VAR := $(shell ...), otherwise every time MY_VAR is evaluated, it'll execute $(shell ...) again.
– Russ Schultz
Aug 25 '15 at 15:57
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How to check if all list items have the same value and return it, or return an “otherValue” if they
... can make it a one-liner by inlining val, but First() would be evaluated n times, doubling execution time.
To incorporate the "empty set" behavior specified in the comments, you simply add one more line before the two above:
if(yyy == null || !yyy.Any()) return otherValue;
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