大约有 40,000 项符合查询结果（耗时：0.0805秒） [XML]
What are bitwise shift (bit-shift) operators and how do they work?
...hift operator, and meets the needs of both logical and arithmetic shifts.
All of these operators can be applied to integer values (int, long, possibly short and byte or char). In some languages, applying the shift operators to any datatype smaller than int automatically resizes the operand to be a...
mysqli or PDO - what are the pros and cons? [closed]
...nvincing somebody works better with a killer feature. So there it is:
A really nice thing with PDO is you can fetch the data, injecting it automatically in an object. If you don't want to use an ORM (cause it's a just a quick script) but you do like object mapping, it's REALLY cool :
class Student...
Trying to understand CMTime and CMTimeMake
...llowing code makes the concept more clear:
1)
Float64 seconds = 5;
int32_t preferredTimeScale = 600;
CMTime inTime = CMTimeMakeWithSeconds(seconds, preferredTimeScale);
CMTimeShow(inTime);
The above code gives:
{3000/600 = 5.000}
Which means a total duration of 5 seconds, with 3000 frames with...
How can I programmatically determine if my app is running in the iphone simulator?
...er "Compiling source code conditionally"
The relevant definition is TARGET_OS_SIMULATOR, which is defined in /usr/include/TargetConditionals.h within the iOS framework. On earlier versions of the toolchain, you had to write:
#include "TargetConditionals.h"
but this is no longer necessary on the ...
Sorting object property by values
...ou like, thus achieving exactly what you set out to do. That would work in all the browsers I know of, but it would be dependent on an implementation quirk, and could break at any time. You should never make assumptions about the order of elements in a JavaScript object.
var objSorted = {}
sortable....
Min/Max of dates in an array?
...
_.min and _.max work on arrays of dates; use those if you're using Lodash or Underscore, and consider using Lodash (which provides many utility functions like these) if you're not already.
For example,
_.min([
new Date(...
Base 64 encode and decode example code
...Charsets:
// Sending side
byte[] data = text.getBytes(StandardCharsets.UTF_8);
String base64 = Base64.encodeToString(data, Base64.DEFAULT);
// Receiving side
byte[] data = Base64.decode(base64, Base64.DEFAULT);
String text = new String(data, StandardCharsets.UTF_8);
...
How to perform mouseover function in Selenium WebDriver using Java?
...
Its not really possible to perform a 'mouse hover' action, instead you need to chain all of the actions that you want to achieve in one go. So move to the element that reveals the others, then during the same chain, move to the now rev...
trying to animate a constraint in swift
...t tapGesture = UITapGestureRecognizer(target: self, action: #selector(doIt(_:)))
textView.addGestureRecognizer(tapGesture)
}
@objc func doIt(_ sender: UITapGestureRecognizer) {
heightConstraint.constant = heightConstraint.constant == 50 ? 150 : 50
UIView.animate(with...
How do I determine if my python shell is executing in 32bit or 64bit?
...test for older systems, this slightly more complicated test should work on all Python 2 and 3 releases:
$ python-32 -c 'import struct;print( 8 * struct.calcsize("P"))'
32
$ python-64 -c 'import struct;print( 8 * struct.calcsize("P"))'
64
BTW, you might be tempted to use platform.architecture() fo...