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Uses for Optional
...tween wanting to use it everywhere something may be null , and nowhere at all.
14 Answers
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How much faster is C++ than C#?
... more advanced JIT optimizations being complicated to implement, and the really cool ones are only arriving just now.
So C++ is faster, in many cases. But this is only part of the answer. The cases where C++ is actually faster, are highly optimized programs, where expert programmers thoroughly opti...
Python: Check if one dictionary is a subset of another larger dictionary
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Convert to item pairs and check for containment.
all(item in superset.items() for item in subset.items())
Optimization is left as an exercise for the reader.
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impr...
Why use #ifndef CLASS_H and #define CLASS_H in .h file but not in .cpp?
...r various reasons. During compilation of your project, each .cpp file (usually) is compiled. In simple terms, this means the compiler will take your .cpp file, open any files #included by it, concatenate them all into one massive text file, and then perform syntax analysis and finally it will conv...
How to prevent XSS with HTML/PHP?
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Basically you need to use the function htmlspecialchars() whenever you want to output something to the browser that came from the user input.
The correct way to use this function is something like this:
echo htmlspecialchars($st...
What exactly is a Context in Java? [duplicate]
...'s ApplicationContext, Android's Context, JNDI's InitialContext, etc. They all often follow the Facade Pattern which abstracts the environmental details the enduser doesn't need to know about away in a single interface/class.
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How to find a Java Memory Leak
... supposed to be able to find the root reference ( ref ) or whatever it is called. Basically, I can tell that there are several hundred megabytes of hash table entries ([java.util.HashMap$Entry or something like that), but maps are used all over the place... Is there some way to search for large maps...
How to print number with commas as thousands separators?
...For Python ≥3.6
Locale aware
import locale
locale.setlocale(locale.LC_ALL, '') # Use '' for auto, or force e.g. to 'en_US.UTF-8'
'{:n}'.format(value) # For Python ≥2.7
f'{value:n}' # For Python ≥3.6
Reference
Per Format Specification Mini-Language,
The ',' option signals the use ...
How to name and retrieve a stash by name in git?
...apply by doing git stash apply stashname . But it seems that in this case all that happens is that stashname will be used as the stash description.
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How to disable GCC warnings for a few lines of code
...n GCC and Clang.
Consider the following Makefile
CPPFLAGS:=-std=c11 -W -Wall -pedantic -Werror
.PHONY: all
all: puts
for building the following puts.c source code
#include <stdio.h>
int main(int argc, const char *argv[])
{
while (*++argv) puts(*argv);
return 0;
}
It will not c...