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Regular expression for floating point numbers
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TL;DR
Use [.] instead of \. and [0-9] instead of \d to avoid escaping issues in some languages (like Java).
Thanks to the nameless one for originally recognizing this.
One relatively simple pattern for matching a floating point number is
[+-]?([0-9]...
What should main() return in C and C++?
...t is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments?
If int main() then return 1 or return 0 ?
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Equation (expression) parser with precedence?
...'ve developed an equation parser using a simple stack algorithm that will handle binary (+, -, |, &, *, /, etc) operators, unary (!) operators, and parenthesis.
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How can I multiply and divide using only bit shifting and adding?
How can I multiply and divide using only bit shifting and adding?
14 Answers
14
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What exactly is a C pointer if not a memory address?
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The C standard does not define what a pointer is internally and how it works internally. This is intentional so as not to limit the number of platforms, where C can be implemented as a compiled or interpreted language.
A pointer val...
Why does Lua have no “continue” statement?
I have been dealing a lot with Lua in the past few months, and I really like most of the features but I'm still missing something among those:
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Get a specific bit from byte
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Easy. Use a bitwise AND to compare your number with the value 2^bitNumber, which can be cheaply calculated by bit-shifting.
//your black magic
var bit = (b & (1 << bitNumber-1)) != 0;
EDIT: To add a little more detail because there ...
Reference: mod_rewrite, URL rewriting and “pretty links” explained
...plained. mod_rewrite is one way to make "pretty links", but it's complex and its syntax is very terse, hard to grok, and the documentation assumes a certain level of proficiency in HTTP. Can someone explain in simple terms how "pretty links" work and how mod_rewrite can be used to create them?
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What is the usefulness of PUT and DELETE HTTP request methods?
... origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI …
For the full specification visit:
http://www.w3.org/Protocols/rfc2616/rf...
Approximate cost to access various caches and main memory?
Can anyone give me the approximate time (in nanoseconds) to access L1, L2 and L3 caches, as well as main memory on Intel i7 processors?
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