大约有 48,000 项符合查询结果（耗时：0.0629秒） [XML]
JavaScript: What are .extend and .prototype used for?
I am relatively new to JavaScript and keep seeing .extend and .prototype in third party libraries I am using. I thought it had to do with the Prototype javascript library, but I am beginning to think that is not the case. What are these used for?
...
Get last record in a queryset
...no real
effect (the ordering was undefined
prior to calling reverse(), and will
remain undefined afterward).
share
|
improve this answer
|
follow
|
...
Extract substring in Bash
...he form someletters_12345_moreleters.ext , I want to extract the 5 digits and put them into a variable.
22 Answers
...
How does the const constructor actually work?
...calized" instance.
That is, all constant expressions begin canonicalized, and later these "canonicalized" symbols are used to recognize equivalence of these constants.
Canonicalization:
A process for converting data that has more than one possible representation into a "standard" canonical repres...
what's the meaning of '=?' in angularJS directive isolate scope declaration?
... or =attr - set up bi-directional binding between a local scope
property and the parent scope property of name defined via the value
of the attr attribute. If no attr name is specified then the
attribute name is assumed to be the same as the local name. Given
<widget my-attr="parentModel"...
XAMPP - MySQL shutdown unexpectedly
When I open XAMPP and click start MySQL button and it gives me an error.
I had started it just before, but now it isn't working.
...
What's better at freeing memory with PHP: unset() or $var = null
...is garbage-collected.) (bug 33595)
The question "difference between unset and = null" details some differences:
unset($a) also removes $a from the symbol table; for example:
$a = str_repeat('hello world ', 100);
unset($a);
var_dump($a);
Outputs:
Notice: Undefined variable: a in xxx
NULL
But ...
UITableView - scroll to the top
...d:YES];
Or
[mainTableView setContentOffset:CGPointZero animated:YES];
And in Swift:
mainTableView.setContentOffset(CGPointZero, animated:true)
And in Swift 3 & above:
mainTableView.setContentOffset(.zero, animated: true)
...
Detect if a NumPy array contains at least one non-numeric value?
...
This should be faster than iterating and will work regardless of shape.
numpy.isnan(myarray).any()
Edit: 30x faster:
import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
'numpy.isnan(a).any()',
'any(n...
How does Python 2 compare string and int? Why do lists compare as greater than numbers, and tuples g
...ring for string, numeric ordering for integers).
When you order a numeric and a non-numeric type, the numeric type comes first.
>>> 5 < 'foo'
True
>>> 5 < (1, 2)
True
>>> 5 < {}
True
>>> 5 < [1, 2]
True
When you order two incompatible types where n...