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Find MongoDB records where array field is not empty
...se, you can compare with the operator $gt but could lead to unexpected results (you can find a detailled explanation in this answer):
ME.find({ pictures: { $gt: [] } })
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Find index of last occurrence of a substring in a string
...rfind('l')
3
Also don't use str as variable name or you'll shadow the built-in str().
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How do I call an Angular.js filter with multiple arguments?
As from the documentation , we can call a filter such as date like this:
6 Answers
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PHPExcel auto size column width
...he column width based on the calculated value of the column (so on the result of any formulae), and any additional characters added by format masks such as thousand separators.
By default, this is an estimated width: a more accurate calculation method is available, based on using GD, which can als...
How can I make git accept a self signed certificate?
...Flow If we are in a work environment where our employer is the MITM, what alternative is there to globally disabling TLS/SSL?
– Stevoisiak
Sep 27 '17 at 17:18
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Create an empty data.frame
...ypes for each column and name them, but not have any rows created as a result.
17 Answers
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How to use the 'sweep' function
...ariance. On line 19 of the code the centering vector is derived:
center <- if (center)
colSums(wt * x)
else 0
and on line 54 it is swept out of the matrix
x <- sqrt(wt) * sweep(x, 2, center, check.margin = FALSE)
The author of the code is using the default value FUN = "-", ...
Find objects between two dates MongoDB
... created_at: {
$gte: ISODate("2010-04-29T00:00:00.000Z"),
$lt: ISODate("2010-05-01T00:00:00.000Z")
}
})
=> { "_id" : ObjectId("4c0791e2b9ec877893f3363b"), "name" : "example", "created_at" : "Sun May 30 2010 00:00:00 GMT+0300 (EEST)" }
Based on my experiments you will need to...
Best practice to validate null and empty collection in Java
...er method to do it:
public static boolean isNullOrEmpty( final Collection< ? > c ) {
return c == null || c.isEmpty();
}
public static boolean isNullOrEmpty( final Map< ?, ? > m ) {
return m == null || m.isEmpty();
}
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Scala @ operator
...tern. Patterns can be used in pattern matching, the left hand side of the <- in for comprehensions, and in destructuring assigments.
scala> val d@(c@Some(a), Some(b)) = (Some(1), Some(2))
d: (Some[Int], Some[Int]) = (Some(1),Some(2))
c: Some[Int] = Some(1)
a: Int = 1
b: Int = 2
scala> (So...