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Check if image exists on server using JavaScript?
...
212
You could use something like:
function imageExists(image_url){
var http = new XMLHttpReq...
Running a cron every 30 seconds
...p commands in sync.
* * * * * /path/to/executable param1 param2
* * * * * ( sleep 30 ; /path/to/executable param1 param2 )
You'll see I've added comments and formatted to ensure it's easy to keep them synchronised.
Both cron jobs actually run every minute but the latter one will wait h...
Dynamic constant assignment
...s called. For example:
def foo
p "bar".object_id
end
foo #=> 15779172
foo #=> 15779112
Perhaps if you explained your use case—why you want to change the value of a constant in a method—we could help you with a better implementation.
Perhaps you'd rather have an instance variable on ...
Rails has_and_belongs_to_many migration
...
260
You need to add a separate join table with only a restaurant_id and user_id (no primary key), ...
Should MySQL have its timezone set to UTC?
...ime from
timestamp columns
Warning! UTC has leap seconds, these look like '2012-06-30 23:59:60' and can
be added randomly, with 6 months prior notice, due to the slowing of
the earths rotation
GMT confuses seconds, which is why UTC was invented.
Warning! different regional timezones might produce t...
How to increase the max upload file size in ASP.NET?
...
Philipp M
1,80977 gold badges2727 silver badges3737 bronze badges
answered Nov 13 '08 at 22:56
Eric RosenbergerEric Rosenberger
...
How do I split a string into an array of characters? [duplicate]
...
221
You can split on an empty string:
var chars = "overpopulation".split('');
If you just wan...
How do I install package.json dependencies in the current directory using npm
...
ireddickireddick
6,19822 gold badges1919 silver badges2121 bronze badges
...
Implements vs extends: When to use? What's the difference?
... //specify what must happen
return 1;
}
public int getNb2() {
//specify what must happen
return 2;
}
}
public class SubClass extends SuperClass {
//you can override the implementation
@Override
public int getNb2() {
return 3;
...
Debug.Assert vs Exception Throwing
...
answered Sep 23 '09 at 20:39
Eric LippertEric Lippert
599k164164 gold badges11551155 silver badges20142014 bronze badges
...