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Replacing NAs with latest non-NA value
In a data.frame (or data.table), I would like to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
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Facebook database design?
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Keep a friend table that holds the UserID and then the UserID of the friend (we will call it FriendID). Both columns would be foreign keys back to the Users table.
Somewhat useful example:
Table Name: User
Columns:
UserID PK
Emai...
Hide separator line on one UITableViewCell
I'm customizing a UITableView . I want to hide the line separating on the last cell ... can i do this?
37 Answers
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How many database indexes is too many?
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It depends on the operations that occur on the table.
If there's lots of SELECTs and very few changes, index all you like.... these will (potentially) speed the SELECT statements up.
If the table is heavily hit by UPDATEs, INSERTs + DELETEs ... these will be very slow w...
How do I loop through or enumerate a JavaScript object?
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object literal iteration
Browser support you can see on Kangax's compat table
For old browser you have
Convert tuple to list and back
...on. NumPy's main object is the homogeneous multidimensional array. It is a table of elements (usually numbers), all of the same type, indexed by a tuple of positive integers.
– pradyunsg
Dec 4 '16 at 3:25
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addEventListener not working in IE8
...e) if you delegate the event handling to another element, for example your table
$('idOfYourTable').on("click", "input:checkbox", function(){
});
in this way you will have only one event handler, and this will work also for newly added elements. This requires jQuery >= 1.7
Otherwise use dele...
SELECT * FROM X WHERE id IN (…) with Dapper ORM
...er supports this directly. For example...
string sql = "SELECT * FROM SomeTable WHERE id IN @ids"
var results = conn.Query(sql, new { ids = new[] { 1, 2, 3, 4, 5 }});
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Make a div fill up the remaining width
...) allowed width to be set, b) has the best browser support and c) wasn't a table
– Jayen
May 21 '15 at 5:27
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How do I know which version of Javascript I'm using?
...ly partially, you may find 97% of ES6, 39% of ES7, kangax.github.io/compat-table/es6, and even these tables are not quite true.
– prosti
Dec 4 '16 at 21:59
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