大约有 46,000 项符合查询结果（耗时：0.0458秒） [XML]
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
I have two Python dictionaries, and I want to write a single expression that returns these two dictionaries, merged (i.e. taking the union). The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place.
...
How to generate a random string of a fixed length in Go?
I want a random string of characters only (uppercase or lowercase), no numbers, in Go. What is the fastest and simplest way to do this?
...
How to implement a queue using two stacks?
Suppose we have two stacks and no other temporary variable.
20 Answers
20
...
Array slicing in Ruby: explanation for illogical behaviour (taken from Rubykoans.com)
I was going through the exercises in Ruby Koans and I was struck by the following Ruby quirk that I found really unexplainable:
...
Cannot create or edit Android Virtual Devices (AVD) from Eclipse, ADT 22.6
...T 22.6.0 ONLY, THESE BUGS SUBSEQUENTLY FIXED IN FOLLOWING BUILDS
Download and install new ADT v22.6.1 from here (zip) or use SDK manager to update
Seems like some bug from Google side, this problem found after "ADT 22.6" update. Widely reported on "Android Open Source Project - Issue Tracker" and ...
Javascript reduce on array of objects
...
After the first iteration your're returning a number and then trying to get property x of it to add to the next object which is undefined and maths involving undefined results in NaN.
try returning an object contain an x property with the sum of the x properties of the parame...
How do I capture the output into a variable from an external process in PowerShell?
I'd like to run an external process and capture it's command output to a variable in PowerShell. I'm currently using this:
...
Swift Beta performance: sorting arrays
I was implementing an algorithm in Swift Beta and noticed that the performance was very poor. After digging deeper I realized that one of the bottlenecks was something as simple as sorting arrays. The relevant part is here:
...
How can building a heap be O(n) time complexity?
...?
Often, answers to these questions focus on the difference between siftUp and siftDown. Making the correct choice between siftUp and siftDown is critical to get O(n) performance for buildHeap, but does nothing to help one understand the difference between buildHeap and heapSort in general. Indeed, ...
What is the scope of variables in JavaScript?
...
TLDR
JavaScript has lexical (also called static) scoping 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)
Bloc...