大约有 15,000 项符合查询结果（耗时：0.0415秒） [XML]
Will console.log reduce JavaScript execution performance?
Will use of the debugging feature console.log reduce JavaScript execution performance? Will it affect the speed of script execution in production environments?
...
How do I get the width and height of a HTML5 canvas?
...
It might be worth looking at a tutorial: Firefox Canvas Tutorial
You can get the width and height of a canvas element simply by accessing those properties of the element. For example:
var canvas = document.getElementById('mycanvas');
var width = canvas.width;
var heigh...
Window vs Page vs UserControl for WPF navigation?
...a page inside your Window. It is mostly used for web-based systems like an XBAP, where you have a single browser window and different pages can be hosted in that window. It can also be used in Navigation Applications like sellmeadog said.
A UserControl is a reusable user-created control that you ca...
Why is semicolon allowed in this python snippet?
...
It seems useful for exec statements e.g. exec('for a in [1,2,3]:print a;print a+1')
– Phil C
Jun 30 '13 at 8:28
...
What's the u prefix in a Python string?
...
You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.
...
Checking for NULL pointer in C/C++ [closed]
...
In my experience, tests of the form if (ptr) or if (!ptr) are preferred. They do not depend on the definition of the symbol NULL. They do not expose the opportunity for the accidental assignment. And they are clear and succinct.
E...
AngularJS performs an OPTIONS HTTP request for a cross-origin resource
...hich delivers my template files is on a different domain and therefore the XHR request that angular performs must be cross-domain. I've added the appropriate CORS header to my server for the HTTP request to make this work, but it doesn't seem to work. The problem is that when I inspect the HTTP requ...
Error installing mysql2: Failed to build gem native extension
...d other distributions using yum:
sudo yum install mysql-devel
On Mac OS X with Homebrew:
brew install mysql
share
|
improve this answer
|
follow
|
...
Meaning of 'const' last in a function declaration of a class?
...o in the const version. If you change the method declaration in the above example to the code below you will get some errors.
void Foo()
{
counter++; //this works
std::cout << "Foo" << std::endl;
}
void Foo() const
{
counter++; //this wil...
Coroutine vs Continuation vs Generator
...rning, but when called will return (yield) a value and then suspend their execution. When they're called again, they will start up from where they last suspended execution and do their thing again.
A generator is essentially a cut down (asymmetric) coroutine. The difference between a coroutine and ...