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How to check type of variable in Java?
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Java is a statically typed language, so the compiler does most of this checking for you. Once you declare a variable to be a certain type, the compiler will ensure that it is only ever assigned values of that type (or values that are sub-ty...
In where shall I use isset() and !empty()
... it's not a good idea to use this operator for math in case "0" is accidentally a string. This can be dangerous. Instead, use basic >, < and == operators and convert variables using intval() or floatval().
– kaleazy
Feb 14 at 18:08
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Using global variables in a function
...ce global variables are so dangerous, Python wants to make sure that you really know that's what you're playing with by explicitly requiring the global keyword.
See other answers if you want to share a global variable across modules.
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How to sort a dataframe by multiple column(s)
...as speedy as the base R commands with their convoluted machinations. Typically brilliant Hadley Wickham work. My only gripe with it is that it breaks the standard R nomenclature where sorting objects get called by sort(object), but I understand why Hadley did it that way due to issues discussed in...
Real mouse position in canvas [duplicate]
... evt.clientX - rect.left,
y: evt.clientY - rect.top
};
}
Just call it from your event with the event and canvas as arguments. It returns an object with x and y for the mouse positions.
As the mouse position you are getting is relative to the client window you'll have to subtract the pos...
MySQL query String contains
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Quite simple actually:
mysql_query("
SELECT *
FROM `table`
WHERE `column` LIKE '%{$needle}%'
");
The % is a wildcard for any characters set (none, one or many). Do note that this can get slow on very large datasets so if your database grow...
Looking to understand the iOS UIViewController lifecycle
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All these commands are called automatically at the appropriate times by iOS when you load/present/hide the view controller. It's important to note that these methods are attached to UIViewController and not to UIViews themsel...
How to save an HTML5 Canvas as an image on a server?
I'm working on a generative art project where I would like to allow users to save the resulting images from an algorithm. The general idea is:
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Python how to write to a binary file?
...uct.pack if you need to work on 2.2. But 2.6 has been out for 5 years now; all three Ubuntu LTSs still in support, all three OS X versions in support, the previous major version of CentOS/RHEL, etc., all come with it built in. If you need to support 2.5 or 2.1 or 1.6 or whatever, you probably know...
How to do Base64 encoding in node.js?
...uld be .toString("binary") (atob stands for ascii(base64) to binary, after all)
– 12Me21
Jan 14 at 19:55
@12Me21 I tho...