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Is it possible to make abstract classes in Python?
...ompiler/interpret know that all the methods are from the abstract class in question?
– Charlie Parker
Mar 17 '14 at 3:30
35
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Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
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See the C FAQ, Question 1.32
Q: What is the difference between these initializations?
char a[] = "string literal";
char *p = "string literal";
My program crashes if I try to assign a new value to p[i].
A: A string literal...
How to check if a map contains a key in Go?
...
@Mheni, I know I'm a bit late here, but this question discusses the lookup complexity in go. Most of the time the amortized complexity is O(1) but it's worth reading the answers on that question.
– 3ocene
Oct 9 '18 at 20:50
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What do 3 dots next to a parameter type mean in Java?
...trings){
// do what ever you want
}
// the code above is equivalent to
for( int i = 0; i < strings.length; i++){
// classical for. In this case you use strings[i]
}
}
This answer borrows heavily from kiswa's and Lorenzo's... and also from Graphain's comment.
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What are the options for storing hierarchical data in a relational database? [closed]
...d. Use an Adjacency List to maintain the hierarchy and use Nested Sets to query the hierarchy.
The problem up until now has been that the coversion method from an Adjacecy List to Nested Sets has been frightfully slow because most people use the extreme RBAR method known as a "Push Stack" to do th...
What are bitwise operators?
... several cases.
x << y
is the same as
x * 2y
if you need to quickly multiply by a power of two, but watch out for shifting a 1-bit into the top bit - this makes the number negative unless it's unsigned. It's also useful when dealing with different sizes of data. For example, reading...
How do you get the list of targets in a makefile?
...al order - i.e.: invoke as make list:
.PHONY: list
list:
@$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | egrep -v -e '^[^[:alnum:]]' -e '^$@$$'
Important: On pasting this, make...
Get list of passed arguments in Windows batch script (.bat)
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%~dp0 - drive and path to the script (d:\scripts)
%~dpnx0 - is the fully qualified path name of the script (d:\scripts\some-batch.bat)
More info examples at https://www.ss64.com/nt/syntax-args.html and https://www.robvanderwoude.com/parameters.html
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What is the difference between Lisp-1 and Lisp-2?
...s of taste between the two, but read the paper for the details. Christian Queinnec's book, "Lisp in Small Pieces" also has discussion of the differences woven through the text.
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How to destroy an object?
...hp's GC if you're doing daemons or similar. In the majority of sites the request is so short lived that it doesn't matter. php.net/manual/en/features.gc.refcounting-basics.php
– Frankie
Sep 11 '15 at 11:38
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