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Declaring variables inside or outside of a loop

....Test extends java.lang.Object{ public inside.Test(); Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object."<init>":()V 4: return public static void main(java.lang.String[]); Code: 0: invokestatic #2; //Method java/lang/System.currentTimeMillis:()J 3...
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How to initialize a private static const map in C++?

...ap> using namespace std; struct A{ static map<int,int> create_map() { map<int,int> m; m[1] = 2; m[3] = 4; m[5] = 6; return m; } static const map<int,int> myMap; }; const map<int,int> A:: myMap = ...
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How to throw an exception in C?

...m Wikipedia #include <stdio.h> #include <setjmp.h> static jmp_buf buf; void second(void) { printf("second\n"); // prints longjmp(buf,1); // jumps back to where setjmp // was called - making setjmp now return 1 } void firs...
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How do I perform the SQL Join equivalent in MongoDB?

...ttps://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup From the docs: { $lookup: { from: <collection to join>, localField: <field from the input documents>, foreignField: <field from the documents of the "from" collection&gt...
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How do I print the elements of a C++ vector in GDB?

...td::vector<int> called myVector, do the following: print *(myVector._M_impl._M_start)@myVector.size() To print only the first N elements, do: print *(myVector._M_impl._M_start)@N Explanation This is probably heavily dependent on your compiler version, but for GCC 4.1.2, the pointer to t...
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Find which version of package is installed with pip

...hat is the difference between using pip list and doing import X and then X.__version__? Are both the package versions? – variable Oct 13 '19 at 4:27 ...
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git rebase without changing commit timestamps

...rresponding author dates, you can run: git filter-branch --env-filter 'GIT_COMMITTER_DATE=$GIT_AUTHOR_DATE; export GIT_COMMITTER_DATE' share | improve this answer | follow ...
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What is the difference between join and merge in Pandas?

...andas as pd left = pd.DataFrame({'key': ['foo', 'bar'], 'val': [1, 2]}).set_index('key') right = pd.DataFrame({'key': ['foo', 'bar'], 'val': [4, 5]}).set_index('key') left.join(right, lsuffix='_l', rsuffix='_r') val_l val_r key foo 1 4 bar 2 5 The same functi...
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How to check if a python module exists without importing it

...mport can find something in python2, using imp import imp try: imp.find_module('eggs') found = True except ImportError: found = False To find dotted imports, you need to do more: import imp try: spam_info = imp.find_module('spam') spam = imp.load_module('spam', *spam_info) i...
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What's the difference between dynamic (C# 4) and var?

... { [CompilerGenerated] private static class <Main>o__SiteContainer0 { public static CallSite<Action<CallSite, object>> <>p__Site1; } private static void Main(string[] args) { Junk a = new Junk(); /...