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Performance difference for control structures 'for' and 'foreach' in C#
...uld all depend upon how the enumerator is implemented versus how the lists indexer is implemented. As it turns out the enumerator for types based on arrays are normally written something like this:
private static IEnumerable<T> MyEnum(List<T> list)
{
for (int i = 0; i < list.Coun...
Select something that has more/less than x character
...). In Oracle, and probably in all other RDBMSs, this means that a regular index on EmployeeName will be useless to answer this query; the database will do a full table scan, which can be really costly.
However, various databases offer a function indexes feature that is designed to speed up queries...
Should I URL-encode POST data?
I'm POSTing data to an external API (using PHP, if it's relevant).
4 Answers
4
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Best way to iterate through a Perl array
...is special-cased to avoid flattening the array. The loop iterates over the indexes of the array.
In terms of readability: #1.
In terms of flexibility: #1/#4 and #5.
#2 does not support elements that are false. #2 and #3 are destructive.
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When to use single quotes, double quotes, and backticks in MySQL
...
Michael all sorted now thanks. Might I suggest editing the chart to add bound variables. It is absolutely gorgeous and if another poor soul came along checking on :whatever that would be even more lovely. ATB Steve
...
Zero-pad digits in string
...
First of all, your description is misleading. Double is a floating point data type. You presumably want to pad your digits with leading zeros in a string. The following code does that:
$s = sprintf('%02d', $digit);
For more informa...
Is there a naming convention for MySQL?
... or remove columns from a table at a later date.
Some other points are:
Index Naming Conventions
You may wish to introduce a naming convention for indexes - this will be a great help for any database metadata work that you might want to carry out. For example you might just want to call an index...
Get user info via Google API
... could have edited it yourself, but don't worry as I have done it now. For all we know they could have omitted the code define(email, 'email') ;)
– verbumSapienti
Apr 23 '14 at 13:03
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Why is the order in dictionaries and sets arbitrary?
... if two objects have the same hash they can be unequal.)
You then make in index by taking the modulus by the array length:
hash(4) % len(storage) = index 2
This makes it really fast to access elements.
Hashes are only most of the story, as hash(n) % len(storage) and hash(m) % len(storage) can r...
Using curl to upload POST data with files
... file" \
-F "image=@/home/user1/Desktop/test.jpg" \
localhost/uploader.php
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