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“Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP
... can be used to detect if a variable has been already initialized. Additionally and more ideal is the solution of empty() since it does not generate a warning or error message if the variable is not initialized.
From PHP documentation:
No warning is generated if the variable does not exist. T...
What is the difference between Directory.EnumerateFiles vs Directory.GetFiles?
...many files and directories, EnumerateFiles can be more efficient.
So basically, EnumerateFiles returns an IEnumerable which can be lazily evaluated somewhat, whereas GetFiles returns a string[] which has to be fully populated before it can return.
...
The purpose of Model View Projection Matrix
...d space to camera space, projection from camera to screen.
If you compose all three, you can use the one result to map all the way from object space to screen space, making you able to work out what you need to pass on to the next stage of a programmable pipeline from the incoming vertex positions....
How to create PDF files in Python [closed]
...ich takes some images from user and then creates a PDF file which contains all of these images.
14 Answers
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Concatenate text files with Windows command line, dropping leading lines
...is via the command line. Unfortunately I only have Windows, and cannot install new software.
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How do you turn a Mongoose document into a plain object?
...ng is that JSON.parse(JSON.encode(doc)) works and returns an object with all of the correct properties. Is there a better way to do this?
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How Python web frameworks, WSGI and CGI fit together
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How WSGI, CGI, and the frameworks are all connected?
Apache listens on port 80. It gets an HTTP request. It parses the request to find a way to respond. Apache has a LOT of choices for responding. One way to respond is to use CGI to run a script. Another w...
Saving an Object (Data persistence)
...ics.
cPickle (or _pickle) vs pickle
It's almost always preferable to actually use the cPickle module rather than pickle because the former is written in C and is much faster. There are some subtle differences between them, but in most situations they're equivalent and the C version will provide gr...
Assembly code vs Machine code vs Object code?
...e to machine code with the use of an assembler or a compiler, though we usually think of compilers in association with high-level programming language that are abstracted further from the CPU instructions.
Building a complete program involves writing source code for the program in either assembly or...