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Single quotes vs. double quotes in C or C++
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In C and in C++ single quotes identify a single character, while double quotes create a string literal. 'a' is a single a character literal, while "a" is a string literal containing an 'a' and a null terminator (that is a 2 char array).
In C++ the type of a character lite...
Base64 length calculation?
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Each character is used to represent 6 bits (log2(64) = 6).
Therefore 4 chars are used to represent 4 * 6 = 24 bits = 3 bytes.
So you need 4*(n/3) chars to represent n bytes, and this needs to be rounded up to a multiple of 4.
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How can I validate a string to only allow alphanumeric characters in it?
...n I validate a string using Regular Expressions to only allow alphanumeric characters in it?
10 Answers
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Unmangling the result of std::type_info::name
...clude <string>
#include <typeinfo>
std::string demangle(const char* name);
template <class T>
std::string type(const T& t) {
return demangle(typeid(t).name());
}
#endif
In file type.cpp (requires C++11)
#include "type.hpp"
#ifdef __GNUG__
#include <cstdlib>
#in...
iterating over each character of a String in ruby 1.8.6 (each_char)
I am new to ruby and currently trying to operate on each character separately from a base String in ruby. I am using ruby 1.8.6 and would like to do something like:
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Java: parse int value from a char
I just want to know if there's a better solution to parse a number from a character in a string (assuming that we know that the character at index n is a number).
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Best way to serialize an NSData into a hexadeximal string
... string of NSData. Empty string if data is empty. */
const unsigned char *dataBuffer = (const unsigned char *)[self bytes];
if (!dataBuffer)
return [NSString string];
NSUInteger dataLength = [self length];
NSMutableString *hexString = [NSMutableString stri...
What does int argc, char *argv[] mean?
...ention, but they can be given any valid identifier: int main(int num_args, char** arg_strings) is equally valid.
They can also be omitted entirely, yielding int main(), if you do not intend to process command line arguments.
Try the following program:
#include <iostream>
int main(int argc,...
Is there an auto increment in sqlite?
... In case it is not obvious from answer, you can use ROWID in your select statement e.g. select rowid from people;
– Colin D
Mar 20 '17 at 15:37
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What is the difference between static_cast and C style casting?
...situations where all that is needed is a simple conversion. The ability to select between several different casting operators of differing degrees of power can prevent programmers from inadvertently casting to an incorrect type.
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