大约有 16,000 项符合查询结果(耗时:0.0293秒) [XML]

https://stackoverflow.com/ques... 

Getting multiple keys of specified value of a generic Dictionary?

...; } // Note potential ambiguity using indexers (e.g. mapping from int to int) // Hence the methods as well... public IList<TSecond> this[TFirst first] { get { return GetByFirst(first); } } public IList<TFirst> this[TSecond second] { get {...
https://stackoverflow.com/ques... 

Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]

...data directly): struct __attribute__((__packed__)) LocalFileHeader { uint32_t signature; uint16_t minVersion, flag, method, modTime, modDate; uint32_t crc32, compressedSize, uncompressedSize; uint16_t nameLength, extraLength; }; The packed attribute prevents the compiler from alig...
https://stackoverflow.com/ques... 

appending array to FormData and send via AJAX

... You have several options: Convert it to a JSON string, then parse it in PHP (recommended) JS var json_arr = JSON.stringify(arr); PHP $arr = json_decode($_POST['arr']); Or use @Curios's method Sending an array via FormData. Not recommended: Seriali...
https://stackoverflow.com/ques... 

Property getters and setters

...you'll need something to backup the computed property. Try this: class Point { private var _x: Int = 0 // _x -> backingX var x: Int { set { _x = 2 * newValue } get { return _x / 2 } } } Specifically, in the Swift REPL: 15> var pt = Point() pt: Point = { _x = 0...
https://stackoverflow.com/ques... 

Fling gesture detection on grid layout

...vity extends Activity implements OnClickListener { private static final int SWIPE_MIN_DISTANCE = 120; private static final int SWIPE_MAX_OFF_PATH = 250; private static final int SWIPE_THRESHOLD_VELOCITY = 200; private GestureDetector gestureDetector; View.OnTouchListener gestureListener; ...
https://stackoverflow.com/ques... 

Difference between null and empty (“”) Java String

...not, 20 is a number). Same case for null: it's not a string, but it can be converted to one if you try to add it. – daboross Mar 4 '18 at 9:13 ...
https://stackoverflow.com/ques... 

How to initialize const member variable in a class?

...ypically declared in a header file and a header file is typically included into many translation units. However, to avoid complicated linker rules, C++ requires that every object has a unique definition. That rule would be broken if C++ allowed in-class definition of entities that needed to be store...
https://stackoverflow.com/ques... 

“is” operator behaves unexpectedly with integers

...id(b) 11662828 Here's what I found in the Python 2 documentation, "Plain Integer Objects" (It's the same for Python 3): The current implementation keeps an array of integer objects for all integers between -5 and 256, when you create an int in that range you actually just get back a re...
https://stackoverflow.com/ques... 

How do I shuffle an array in Swift?

...) in zip(indices, stride(from: c, to: 1, by: -1)) { // Change `Int` in the next line to `IndexDistance` in < Swift 4.1 let d: Int = numericCast(arc4random_uniform(numericCast(unshuffledCount))) let i = index(firstUnshuffled, offsetBy: d) swapAt(firs...
https://stackoverflow.com/ques... 

Haversine Formula in Python (Bearing and Distance between two GPS points)

... two points on the earth (specified in decimal degrees) """ # convert decimal degrees to radians lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2]) # haversine formula dlon = lon2 - lon1 dlat = lat2 - lat1 a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) ...