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What's the difference between utf8_general_ci and utf8_unicode_ci?
...languages or characters.
On modern servers, this performance boost will be all but negligible. It was devised in a time when servers had a tiny fraction of the CPU performance of today's computers.
Benefits of utf8mb4_unicode_ci over utf8mb4_general_ci
utf8mb4_unicode_ci, which uses the Unicode r...
Regular Expression for alphanumeric and underscores
...o or more of the given characters
$ : end of string
If you don't want to allow empty strings, use + instead of *.
As others have pointed out, some regex languages have a shorthand form for [a-zA-Z0-9_]. In the .NET regex language, you can turn on ECMAScript behavior and use \w as a shorthand (y...
UIPanGestureRecognizer - Only vertical or horizontal
I have a view that has a UIPanGestureRecognizer to drag the view vertically. So in the recognizer callback, I only update the y-coordinate to move it. The superview of this view, has a UIPanGestureRecognizer that will drag the view horizontally, just updating the x-coordinate.
...
How do I concatenate or merge arrays in Swift?
...ith Sequence's flatMap(_:) method
Swift provides a flatMap(_:) method for all types that conform to Sequence protocol (including Array). flatMap(_:) has the following declaration:
Returns an array containing the concatenated results of calling the given transformation with each element of this ...
What's the difference between hard and soft floating point numbers?
...t float) in accuracy-critical parts and fast (hard float) in parts where small deviations don't matter.
– PhilLab
May 29 '17 at 12:18
...
How can I read SMS messages from the device programmatically in Android?
...ForResult(intent, 1);
}else {
List<Sms> lst = getAllSms();
}
}else {
List<Sms> lst = getAllSms();
}
Set app as default SMS app
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1...
Determine if 2 lists have the same elements, regardless of order? [duplicate]
... helper function. Note that it will be quite slow (O(n²)) and should generally not be used outside of the esoteric case of unhashable and unsortable elements.
def equal_ignore_order(a, b):
""" Use only when elements are neither hashable nor sortable! """
unmatched = list(b)
for element...
How can I exclude all “permission denied” messages from “find”?
I need to hide all permission denied messages from:
17 Answers
17
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@property retain, assign, copy, nonatomic in Objective-C
...gners opted for the safer of the two solutions. In fact nonatomic is generally the better choice as it omits extremely expensive thread locks. The only reason to use atomic is if your property might be set from multiple threads (in which case omitting it can lead to an over-release or a leak).
...
In a django model custom save() method, how should you identify a new object?
...
Not all models have an id attribute, i.e. a model extending another through a models.OneToOneField(OtherModel, primary_key=True). I think you need to use self.pk
– AJP
Apr 9 '13 at 10:21
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