大约有 34,900 项符合查询结果（耗时：0.0235秒） [XML]
Simpler way to create dictionary of separate variables?
I would like to be able to get the name of a variable as a string but I don't know if Python has that much introspection capabilities. Something like:
...
Can hash tables really be O(1)?
It seems to be common knowledge that hash tables can achieve O(1), but that has never made sense to me. Can someone please explain it? Here are two situations that come to mind:
...
What is the scope of variables in JavaScript?
...ing and closures. This means you can tell the scope of an identifier by looking at the source code.
The four scopes are:
Global - visible by everything
Function - visible within a function (and its sub-functions and blocks)
Block - visible within a block (and its sub-blocks)
Module - visible within...
How do I use the new computeIfAbsent function?
...oncurrentHashMap<>();
whoLetDogsOut.computeIfAbsent("snoop", k -> f(k));
whoLetDogsOut.computeIfAbsent("snoop", k -> f(k));
}
static boolean f(String s) {
System.out.println("creating a value for \""+s+'"');
return s.isEmpty();
}
}
Then you w...
How to get URL parameter using jQuery or plain JavaScript?
I have seen lots of jQuery examples where parameter size and name are unknown.
33 Answers
...
Installing R with Homebrew
...), the method is the following:
brew tap homebrew/science
brew install Caskroom/cask/xquartz
brew install r
The gcc package (will be installed automatically as a required dependency) in the homebrew/science tap already contains the latest fortran compiler (gfortran), and most of all: the whole pa...
Adding two numbers concatenates them instead of calculating the sum
...
Peter Mortensen
26.5k2121 gold badges9292 silver badges122122 bronze badges
answered Jan 24 '13 at 8:08
elclanrselclanrs
...
Is DateTime.Now the best way to measure a function's performance?
I need to find a bottleneck and need to accurately as possible measure time.
15 Answers
...
Best way to create an empty map in Java
...he latter sometimes when the compiler cannot automatically figure out what kind of Map is needed (this is called type inference). For example, consider a method declared like this:
public void foobar(Map<String, String> map){ ... }
When passing the empty Map directly to it, you have to...
What's the absurd function in Data.Void useful for?
...nature, where Void is the logically uninhabited type exported by that package:
6 Answers
...