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What is the apply function in Scala?
...Every function also has an OO type: for instance, a function that takes an Int parameter and returns an Int will have OO type of Function1[Int,Int].
// define a function in scala
(x:Int) => x + 1
// assign an object representing the function to a variable
val f = (x:Int) => x + 1
Since...
How to extract numbers from a string in Python?
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If you only want to extract only positive integers, try the following:
>>> str = "h3110 23 cat 444.4 rabbit 11 2 dog"
>>> [int(s) for s in str.split() if s.isdigit()]
[23, 11, 2]
I would argue that this is better than the regex example because you ...
Why does C++ require a user-provided default constructor to default-construct a const object?
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But this still forbids struct A { int n; A() = default; }; const A a; while allowing struct B { int n; B() {} }; const B b; because the new wording still says "user-provided" not "user-declared" and I'm left scratching my head why the committee chose to exclu...
Why can't I have “public static const string S = ”stuff"; in my Class?
... value semantics, which means references to the constant might be compiled into the using code as the value of the constant member, instead of a reference to the member.
In other words, a const member containing the value 10, might get compiled into code that uses it as the number 10, instead of a ...
Why are Where and Select outperforming just Select?
... with p(valid) as a variable. The actual values of the costs determine the intersection point of the two lines, and since cost(yield) can be different from cost(+), they don't necessarily intersect at p(valid)=0.5.
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C++ catch blocks - catch exception by value or reference? [duplicate]
...e. If a MyException type was thrown your catch block would cause it to be converted to a CustomException instance which would cause the error code to change.
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Make copy of an array
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You can try using System.arraycopy()
int[] src = new int[]{1,2,3,4,5};
int[] dest = new int[5];
System.arraycopy( src, 0, dest, 0, src.length );
But, probably better to use clone() in most cases:
int[] src = ...
int[] dest = src.clone();
...
How do I use InputFilter to limit characters in an EditText in Android?
... = new InputFilter() {
public CharSequence filter(CharSequence source, int start, int end,
Spanned dest, int dstart, int dend) {
for (int i = start; i < end; i++) {
if (!Character.isLetterOrDigit(source.charAt(i))) {
return "";
}
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is vs typeof
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@nawfal, I initially thought your point about the boxing penalty made sense for struct types, but given that we're testing an object obj; variable, isn't it already boxed when this tends to be tested? Is there a case where you need to test the type of somethin...
How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
It's a sad fact of life on Scala that if you instantiate a List[Int], you can verify that your instance is a List, and you can verify that any individual element of it is an Int, but not that it is a List[Int], as can be easily verified:
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