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How to determine whether an object has a given property in JavaScript
...he in operator.
if ('prop' in obj) {
// ...
}
Eg.:
var obj = {};
'toString' in obj == true; // inherited from Object.prototype
obj.hasOwnProperty('toString') == false; // doesn't contains it physically
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Is there a performance impact when calling ToList()?
...all files' names immediately into memory, it has a potential risk that the string[] costs a lot of memory, slowing down everything.
What should be done then
It depends. If you(as well as your business logic) gurantees that the file amount in the folder is always small, the code is acceptable. But ...
GroupBy pandas DataFrame and select most common value
I have a data frame with three string columns. I know that the only one value in the 3rd column is valid for every combination of the first two. To clean the data I have to group by data frame by first two columns and select most common value of the third column for each combination.
...
Where can I learn how to write C code to speed up slow R functions? [closed]
...rikes me is that you find R somewhat tedious (data manipulation, graphics, string manipulatio, etc ...). Well get prepared for many more surprises with the internal C API of R. This is very tedious.
From time to time, I read the R-exts or R-ints manuals. This helps. But most of the time, when I re...
Set a path variable with spaces in the path in a Windows .cmd file or batch file
...
I use
set "VAR_NAME=<String With Spaces>"
when updating path:
set "PATH=%UTIL_DIR%;%PATH%"
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Pointers vs. values in parameters and return values
...mb for receivers is, "If in doubt, use a pointer."
Slices, maps, channels, strings, function values, and interface values are implemented with pointers internally, and a pointer to them is often redundant.
Elsewhere, use pointers for big structs or structs you'll have to change, and otherwise pass v...
How do I check if I'm running on Windows in Python? [duplicate]
...s the system/OS name, e.g. 'Linux', 'Windows' or 'Java'.
An empty string is returned if the value cannot be determined.
If that isn't working, maybe try platform.win32_ver and if it doesn't raise an exception, you're on Windows; but I don't know if that's forward compatible to 64-bit, sin...
How to select multiple files with ?
...lement.
when you want to upload multiple file you should use array and not string as the value of the
name attribute.
ex: input type="file" name="myPhotos[]" multiple="multiple"
and if you are using php then you will get the data in $_FILES and
use var_dump($_FILES) and see output and do process...
Wildcards in jQuery selectors
...t;
<div id="jander2"></div>
This will select the given string anywhere in the id.
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ASP.NET MVC - passing parameters to the controller
...lt ViewNextItem(int? id) makes the id integer a nullable type, no need for string<->int conversions.
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