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Performance difference for control structures 'for' and 'foreach' in C#
...date. I did a small test, just to see. Here is the code:
static void Main(string[] args)
{
List<int> intList = new List<int>();
for (int i = 0; i < 10000000; i++)
{
intList.Add(i);
}
DateTime timeStarted = DateTime.Now;
for (int i = 0; i < intList...
What makes a keychain item unique (in iOS)?
...ivate keys. That's a lot different to Apple's sample code that only stores string credentials (username/password). However, I have found out that when you set the kSecClass to kSecClassCertificate or kSecClassKey the Keychain checks also if the entry (the value) is already stored. This prevents from...
Pimpl idiom vs Pure virtual class interface
... important. It's appropriate for it to be a key in a std::map. Example, a "string" class, or a "date" class, or a "complex number" class. To "copy" instances of such a class makes sense.
An Entity type
Identity is important. Always passed by reference, never by "value". Often, doesn't make sense t...
Javascript callback when IFRAME is finished loading?
...cript">
function on_load(iframe) {
try {
// Displays the first 50 chars in the innerHTML of the
// body of the page that the iframe is showing.
// EDIT 2012-04-17: for wider support, fallback to contentWindow.document
var doc = iframe.contentDocument || iframe.contentWindow.docu...
What does the “__block” keyword mean?
...c NSInteger CounterStatic;
{
NSInteger localCounter = 42;
__block char localCharacter;
void (^aBlock)(void) = ^(void) {
++CounterGlobal;
++CounterStatic;
CounterGlobal = localCounter; // localCounter fixed at block creation
localCharacter = 'a'; // sets ...
Loop inside React JSX
...this with a ul (unordered list). <ul> {objects.map((object:string,i:number)=>{ return <li>{object}</li> })} </ul> using TypeScript
– Roberto C Navarro
Sep 28 '15 at 20:10
...
WatiN or Selenium? [closed]
...
{
IE _ie = null;
object _lock = new object();
IE GetInstance(string UrlFragment)
{
lock (_lock)
{
if (_ie == null)
{
var instances = new IECollection(true); //Find all existing IE instances
var match = instanc...
Tab space instead of multiple non-breaking spaces (“nbsp”)?
...
I used this in a case for Swing JTable headers with a String value and an HTML arrow-type character, where I needed this character as a separator. Works great! Thanks!
– Blake Neal
Mar 27 '17 at 19:47
...
Which is more efficient: Multiple MySQL tables or one large table?
...ow on top of a legacy system. I had to expand the old database tables with extra columns. I decided to make new tables for the new data. Some new features come in handy for the legacy system and now I can easily integrate them without having to rewrite too much of the old queries
...
MySQL复制的概述、安装、故障、技巧、工具 - 数据库(内核) - 清泛网 - 专注...
...表可以使用不同的键类型。比如主服务器用InnoDB，键用VARCHAR的话节省空间，从服务器使用MyISAM，键用CHAR提高速度，因为MyISAM有静态表一说。
主从服务器中的表可以使用不同的索引。主服务器主要用来应付写操作，所以除了主...