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What does the “at” (@) symbol do in Python?
...tors, which includes @, which makes it also an operator:
The following tokens are operators:
+ - * ** / // % @
<< >> & | ^ ~
< > <= >= == !=
and in the next page, the Dat...
Error : BinderProxy@45d459c0 is not valid; is your activity running?
...the activity actually was already on the screen. Moreover, deserialization allocates memory for new object, that is completely different from the original one.
The solution is just to bind to the service each time you need it and return a binder that has a method like 'setMessenger(Messenger messen...
Passing an Array as Arguments, not an Array, in PHP
...
As has been mentioned, as of PHP 5.6+ you can (should!) use the ... token (aka "splat operator", part of the variadic functions functionality) to easily call a function with an array of arguments:
<?php
function variadic($arg1, $arg2)
{
// Do stuff
echo $arg1.' '.$arg2;
}
$array ...
PHP Regex to check date is in YYYY-MM-DD format
...tice under any circumstances. Here's how:
explode is limited to return 3 tokens (so that if the input is "1-2-3-4", $d will become "3-4")
ctype_digit is used to make sure that the input does not contain any non-numeric characters (apart from the dashes)
array_pad is used (with a default value that...
Maximum size of an Array in Javascript
...a big deal
x=3e7 takes 1300ms, which is pretty bad
x=4e7 takes 11000ms and allocates an extra 2.5GB of memory
So around 30 million elements is a hard upper limit, because the javascript VM falls off a cliff at 40 million elements and will probably crash the process.
...
When should I use nil and NULL in Objective-C?
...e object. Let's have an example:
NSMutableArray *check = [[NSMutableArray alloc] init];
[check addObject:[NSNull null]];
[check addObject:nil];
On the second line, we will not get any error, because it is perfectly fair to insert a NSNull object into a collection type object. On the third line, w...
apc vs eaccelerator vs xcache
...ich were things under my control. 1) Don't let APC fill up. Make sure to allocate enough memory 2) Don't use apc_clear_cache() on an active server 3) APC doesn't really cope well with heavy lock contention -- don't try to write to a single key from multiple processes simultaneously.
...
MySQL: multiple tables or one table with many columns?
...ple the date-of-birth of a user will not be updated ever, but the back end token may be invalidated after a period of time and will require frequent updates. Would it be better if I separate the tables in this manner to improve the performance? I'll now go read about the wiki that you mentioned :)
...
How do I pass command-line arguments to a WinForms application?
...nt is equal to String.Empty. The remaining elements contain any additional tokens entered on the command line.
– EKanadily
Apr 2 '14 at 7:15
...
How to convert a string into double and vice versa?
...separators, also.
NSNumberFormatter * myNumFormatter = [[NSNumberFormatter alloc] init];
[myNumFormatter setLocale:[NSLocale currentLocale]]; // happen by default?
[myNumFormatter setFormatterBehavior:NSNumberFormatterBehavior10_4];
// next line is very important!
[myNumFormatter setNumberStyle...