大约有 16,000 项符合查询结果（耗时：0.0494秒） [XML]
Check if a div exists with jquery [duplicate]
...he selector doesn't find anything then length === 0 which is "falsy" (when converted to bool its false). So if it finds something then it should be "truthy" - so you don't need to check for > 0. Just for it's "truthyness"
...
Reset auto increment counter in postgres
...
Converted from comment for the sake of visitor's convenience
It's not clear from this message what the correct syntax is. It is:
ALTER SEQUENCE product_id_seq RESTART WITH 1453;
...
Is there a reason for C#'s reuse of the variable in a foreach?
...oop body, as it made no observable difference. When closure semantics were introduced in C# 2.0, the choice was made to put the loop variable outside the loop, consistent with the "for" loop.
I think it is fair to say that all regret that decision. This is one of the worst "gotchas" in C#, and we a...
std::vector versus std::array in C++
...style array. However, it's more secure, since the implicit conversion to pointer is disabled, and it provides much of the STL-related functionality of std::vector and of the other containers, so you can use it easily with STL algorithms & co. Anyhow, for the very limitation of fixed size it's mu...
What are the basic rules and idioms for operator overloading?
... bitshift operators << and >>, although still used in hardware interfacing for the bit-manipulation functions they inherit from C, have become more prevalent as overloaded stream input and output operators in most applications. For guidance overloading as bit-manipulation operators, see...
Interface defining a constructor signature?
It's weird that this is the first time I've bumped into this problem, but:
18 Answers
...
How to escape the % (percent) sign in C's printf?
...rsion specification) causes a '%' character to be written with no argument converted.
The string really has 2 '%' characters inside (as opposed to escaping characters: "a\bc" is a string with 3 non null characters; "a%%b" is a string with 4 non null characters).
...
What is the correct answer for cout
Recently in an interview there was a following objective type question.
4 Answers
4
...
Why does modern Perl avoid UTF-8 by default?
...broken and dangerous. Might as well poke the other eye out, too.
Code that converts unknown characters to ? is broken, stupid, braindead, and runs contrary to the standard recommendation, which says NOT TO DO THAT! RTFM for why not.
Code that believes it can reliably guess the encoding of an unmarke...
Different ways of adding to Dictionary
...is the This indexer:
public TValue this[TKey key]
{
get
{
int index = this.FindEntry(key);
if (index >= 0)
{
return this.entries[index].value;
}
ThrowHelper.ThrowKeyNotFoundException();
return default(TValue);
}
set
...