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How does the String class override the + operator?
...x = "+x;
The compiler converts "x = "+x; into a StringBuilder internally and uses .append(int) to "add" the integer to the string.
5.1.11. String Conversion
Any type may be converted to type String by string conversion.
A value x of primitive type T is first converted to a reference val...
Geometric Mean: is there a built-in?
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Here is a vectorized, zero- and NA-tolerant function for calculating geometric mean in R. The verbose mean calculation involving length(x) is necessary for the cases where x contains non-positive values.
gm_mean = function(x, na.rm=TRUE){
exp(sum(log...
How to validate an Email in PHP?
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You can use the filter_var() function, which gives you a lot of handy validation and sanitization options.
filter_var($email, FILTER_VALIDATE_EMAIL)
PHP Manual filter_var()
Available in PHP >= 5.2.0
If you don't want to change your code that relied on your function, just do:
func...
Linq to SQL how to do “where [column] in (list of values)”
I have a function where I get a list of ids, and I need to return the a list matching a description that is associated with the id. E.g.:
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Algorithm to compare two images
...ctive areas of the image that could represent zoomed portions of the image and various positions and rotations. It starts getting tricky if one of the images are a skewed version of another, these are the sort of limitations you should identify and compromise on.
Matlab is an excellent tool for te...
Angular ng-if=“” with multiple arguments
I am trying to get started on angular development. And after reviewing the documentation some questions persist. How do i best write a ng-if with multiple arguments corresponding to
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Using :before CSS pseudo element to add image to modal
...class Modal which is absolutely positioned, z-indexed above it's parent, and nicely positioned with JQuery. I want to add a caret image (^) to the top of the modal box and was looking at using the :before CSS pseudo selector to do this cleanly.
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Is there a max array length limit in C++?
... the restrictions of the size type used to describe an index in the array (and the size thereof). It is given by the maximum value the system's std::size_t can take. This data type is large enough to contain the size in bytes of any object
The other limit is a physical memory limit. The larger your...
C++: What is the size of an object of an empty class?
... It surely could not be 0 bytes since it should be possible to reference and point to it like any other object. But, how big is such an object?
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How to flip windows in vim? [duplicate]
...tate in a 'column' or 'row' of split windows, C-wC-r
The following commands can be used to change the window layout. For example,
when there are two vertically split windows, CTRL-W K will change that in
horizontally split windows. CTRL-W H does it the other way around.
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