大约有 13,700 项符合查询结果（耗时：0.0312秒） [XML]
How to check whether dynamically attached event listener exists or not?
... finally?
If you wanted to you could something like the following:
var _addEventListener = EventTarget.prototype.addEventListener;
var _removeEventListener = EventTarget.prototype.removeEventListener;
EventTarget.prototype.events = {};
EventTarget.prototype.addEventListener = function(name, list...
What is a NullReferenceException, and how do I fix it?
...ic class Form1
{
private Customer customer;
private void Form1_Load(object sender, EventArgs e)
{
Customer customer = new Customer();
customer.Name = "John";
}
private void Button_Click(object sender, EventArgs e)
{
MessageBox.Show(customer....
Delete multiple objects in django
... to delete any Post with a future publication date
Post.objects.filter(pub_date__gt=datetime.now()).delete()
You do, however, need to come up with a way to narrow down your QuerySet. If you just want a view to delete a particular object, look into the delete generic view.
EDIT:
Sorry for the mi...
Initializing a list to a known number of elements in Python [duplicate]
...x in xrange(N)]
10 loops, best of 3: 109 ms per loop
>>> def fill_list1():
"""Not too bad, but complicated code"""
a = [None] * N
for x in xrange(N):
a[x] = x**2
>>> %timeit fill_list1()
10 loops, best of 3: 126 ms per loop
>>> def fill_list2():
"...
How to validate an Email in PHP?
...
You can use the filter_var() function, which gives you a lot of handy validation and sanitization options.
filter_var($email, FILTER_VALIDATE_EMAIL)
PHP Manual filter_var()
Available in PHP >= 5.2.0
If you don't want to change your code t...
str performance in python
...; import dis
>>> dis.dis(lambda: str(100000))
8 0 LOAD_GLOBAL 0 (str)
3 LOAD_CONST 1 (100000)
6 CALL_FUNCTION 1
9 RETURN_VALUE
>>> dis.dis(lambda: '%s' % 100000)
9 0 LOAD...
Default template arguments for function templates
...
typename Comp = std::less<
typename std::iterator_traits<Iterator>::value_type> >
void sort(Iterator beg, Iterator end, Comp c = Comp()) {
...
}
C++0x introduces them to C++. See this defect report by Bjarne Stroustrup: Default Template Arguments for Functio...
Declare and Initialize String Array in VBA
...
Dim myStringArray() As String
*code*
redim myStringArray(size_of_your_array)
Then you can do something static like this:
myStringArray = { item_1, item_2, ... }
Or something iterative like this:
Dim x
For x = 0 To size_of_your_array
myStringArray(x) = data_source(x).Name
Nex...
How can I count the occurrences of a list item?
...by a constant factor of approximately 2.
Here is the script I used:
from __future__ import print_function
import timeit
t1=timeit.Timer('Counter(l)', \
'import random;import string;from collections import Counter;n=1000;l=[random.choice(string.ascii_letters) for x in range(n)]'
...
Splitting string into multiple rows in Oracle
...st2', 'Err1' from dual
)
select distinct
t.name, t.project,
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) as error
from
temp t,
table(cast(multiset(select level from dual connect by level <= length (regexp_replace(t.error, '[^,]+')) + 1) as sys.OdciNumberList)) levels
...