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Selecting only numeric columns from a data frame
...de
## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numeric)]
Less codey, less reflecting R's particular quirks, and more straightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
...
simple explanation PHP OOP vs Procedural?
... Those can tend to confuse more than help, so feel free to ignore that for now.
You can think of source code simply as "chunks" of functionality, that just happen to be saved to individual files.
There are different ways of organizing those "chunks"; depending on things like conventions of the progr...
Get class name using jQuery
...
But what if you don't know the classname? ;-)
– Potherca
Jun 11 '11 at 20:41
10
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Laravel requires the Mcrypt PHP extension
...P version above.
Then restart the terminal to see which PHP you are using now.
And it should be working now.
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How to find the array index with a value?
..."rollnumber": 3,
"name": "amit",
"subject": "chemistry"
},
];
Now if we have a requirement to select a particular object in the array. Let us assume that we want to find index of student with name Tanmay.
We can do that by iterating through the array and comparing value at the given ke...
Understanding __get__ and __set__ and Python descriptors
... make sure those divisions are / 5.0 and / 9.0). That gives:
100.0
32.0
Now there are other, arguably better ways to achieve the same effect in python (e.g. if celsius were a property, which is the same basic mechanism but places all the source inside the Temperature class), but that shows what c...
What's wrong with using $_REQUEST[]?
...ill have to sanitize this data, but it's one less thing to worry about.
Now you might wonder, why does $_REQUEST exists after all and why it is not removed. This was asked on PHP Internals as well. Citing Rasmus Lerdorf about Why does $_REQUEST exist? on PHP Internals
The more stuff like this...
Why is the default value of the string type null instead of an empty string?
...ublic static string EmptyNull(this string str)
{
return str ?? "";
}
Now this works safely:
string str = null;
string upper = str.EmptyNull().ToUpper();
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Bootstrap dropdown sub menu missing
...Mark Otto..
"Submenus just don't have much of a place on the web right now, especially the mobile web. They will be removed with 3.0" - https://github.com/twbs/bootstrap/pull/6342
But, with a little extra CSS you can get the same functionality.
Bootstrap 4 (navbar submenu on hover)
.navbar-n...
How to ISO 8601 format a Date with Timezone Offset in JavaScript?
...the format required by the spec that you referenced.
This format is also known as ISO8601, or more precisely as RFC3339.
In this format, UTC is represented with a Z while all other formats are represented by an offset from UTC. The meaning is the same as JavaScript's, but the order of subtraction...