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Understanding the map function
...omprehensions instead:
map(f, iterable)
is basically equivalent to:
[f(x) for x in iterable]
map on its own can't do a Cartesian product, because the length of its output list is always the same as its input list. You can trivially do a Cartesian product with a list comprehension though:
[(a,...
How to remove ASP.Net MVC Default HTTP Headers?
...
X-Powered-By is a custom header in IIS. Since IIS 7, you can remove it by adding the following to your web.config:
<system.webServer>
<httpProtocol>
<customHeaders>
<remove name="X-Powered-By...
Can a for loop increment/decrement by more than one?
...ways to increment a for loop in Javascript besides i++ and ++i ? For example, I want to increment by 3 instead of one.
...
Passing an integer by reference in Python
...nd is to pass the integer in a container which can be mutated:
def change(x):
x[0] = 3
x = [1]
change(x)
print x
This is ugly/clumsy at best, but you're not going to do any better in Python. The reason is because in Python, assignment (=) takes whatever object is the result of the right hand...
Best practices for circular shift (rotate) operations in C++
...otate question with some more details about what asm gcc/clang produce for x86.
The most compiler-friendly way to express a rotate in C and C++ that avoids any Undefined Behaviour seems to be John Regehr's implementation. I've adapted it to rotate by the width of the type (using fixed-width types ...
javascript set a variable if undefined
...f the variable is strictly undefined then the safest way is to write:
var x = (typeof x === 'undefined') ? your_default_value : x;
On newer browsers it's actually safe to write:
var x = (x === undefined) ? your_default_value : x;
but be aware that it is possible to subvert this on older browse...
How to avoid warning when introducing NAs by coercion
...
Use suppressWarnings():
suppressWarnings(as.numeric(c("1", "2", "X")))
[1] 1 2 NA
This suppresses warnings.
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Convert Int to String in Swift
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Converting Int to String:
let x : Int = 42
var myString = String(x)
And the other way around - converting String to Int:
let myString : String = "42"
let x: Int? = myString.toInt()
if (x != nil) {
// Successfully converted String to Int
}
Or if ...
In php, is 0 treated as empty?
Code will explain more:
18 Answers
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