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How to randomly pick an element from an array
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I just noticed a notification that I downvoted this answer - I must have clicked it accidentally; unfortunately the interface won't let me undo it (it says I can't change my vote unless the answer is edited...). So, apologies to Chris Dennett.
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Protect .NET code from reverse engineering?
...It took a long time to get here but I finally have seen the light. I went down the road of more restrictive protections and battling the crackers. I learned all I could about reverse engineering in an attempt to prevent my own. I finally figured out the right ideology
– mmcdo...
How can I programmatically create a new cron job?
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if you use a package manager to package your software, you can simply lay down files in that directory and they are interpreted as if they were crontabs, but with an extra field for the username, e.g.:
Filename: /etc/cron.d/per_minute
Content:
* * * * * root /bin/sh /home/root/script.sh
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How do I select a random value from an enumeration?
...s every time instead of caching it in an array. This would slow their code down so I don't see what's your contribution here?
– Bojidar Stanchev
Oct 10 '19 at 10:56
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Error handling in C code
...g a non-throwing variant.
C++ exceptions are relatively expensive but this downside is mostly overblown for programs making sensible use of exceptions. A program simply shouldn't throw exceptions on a codepath where performance is a concern. It doesn't really matter how fast your program can report ...
How to join (merge) data frames (inner, outer, left, right)
... df2:
merge(df1,df2, all.y=TRUE)
you can flip 'em, slap 'em and rub 'em down to get the other two outer joins you asked about :)
Subscript Method
A left outer join with df1 on the left using a subscript method would be:
df1[,"State"]<-df2[df1[ ,"Product"], "State"]
The other combination o...
Struct like objects in Java
...nate in whole pixels any other way. Getters and setters will only slow you down.
On the other hand, with:
public class BankAccount{
public int balance;
}
You might want to change the way a balance is calculated at some point in the future. This should really use getters and setters.
It's al...
how to implement a long click listener on a listview
...ck = false;
}
if (event.getAction() == MotionEvent.ACTION_DOWN) {
isLongClick = false;
}
return super.onTouchEvent(event);
}
@Override
public boolean performLongClick() {
isLongClick = true;
return super.performLongClick();
...
Switching to landscape mode in Android Emulator
...l+F5 Volume up (or + on numeric keyboard with Num Lock off) Ctrl+F6 Volume down (or + on numeric keyboard with Num Lock off) F7 Power Button Ctrl+F3 Camera Button
Ctrl+F11Switch layout orientation portrait/landscape backwards
Ctrl+F12 Switch layout orientation portrait/landscape forwards
F8 Toggl...
When to use IList and when to use List
...headache if you decide to use a Stack or some other data structure further down the road. If all you need to do in the function is foreach through it, IEnumerable<T> is really all you should be asking for.
On the other hand, when returning an object out of a function, you want to give the us...