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Determine if a String is an Integer in Java [duplicate]
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The most naive way would be to iterate over the String and make sure all the elements are valid digits for the given radix. This is about as efficient as it could possibly get, since you must look at each element at least once. I suppose we could micro-optimize it based on the ra...
What are the options for storing hierarchical data in a relational database? [closed]
... thought I'd give Celko a bit of competition by coming up with a method to convert an Adjacency List to Nested sets at speeds that just seem impossible. Here's the performance of the push stack method on my i5 laptop.
Duration for 1,000 Nodes = 00:00:00:870
Duration for 10,000 Nodes = 00:01...
How to create NS_OPTIONS-style bitmask enumerations in Swift?
...C-style enumerations are imported as Swift enumerations. This makes sense, and since enumerations in Swift are readily provided as the enum value type it's easy to see how to create our own.
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How to change the default collation of a table?
...set and collation of a table including those of existing columns (note the convert to clause):
alter table <some_table> convert to character set utf8mb4 collate utf8mb4_unicode_ci;
Edited the answer, thanks to the prompting of some comments:
Should avoid recommending utf8. It's almost n...
How to get first N elements of a list in C#?
...t.Take(5);
Or to slice:
var secondFiveItems = myList.Skip(5).Take(5);
And of course often it's convenient to get the first five items according to some kind of order:
var firstFiveArrivals = myList.OrderBy(i => i.ArrivalTime).Take(5);
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Implement touch using Python?
touch is a Unix utility that sets the modification and access times of files to the current time of day. If the file doesn't exist, it is created with default permissions.
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Difference between Math.Floor() and Math.Truncate()
What is the difference between Math.Floor() and Math.Truncate() in .NET?
12 Answers
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Add column to SQL Server
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Use this query:
ALTER TABLE tablename ADD columname DATATYPE(size);
And here is an example:
ALTER TABLE Customer ADD LastName VARCHAR(50);
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Save and load MemoryStream to/from a file
I am serializing an structure into a MemoryStream and I want to save and load the serialized structure.
9 Answers
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Can I use a binary literal in C or C++?
... 2 formatting with STL streams (since setbase will only honour bases 8, 10 and 16), but you can use either a std::string version of itoa, or (the more concise, yet marginally less efficient) std::bitset.
#include <boost/utility/binary.hpp>
#include <stdio.h>
#include <stdlib.h>
#i...