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What is the difference between require() and library()?
What is the difference between require() and library() ?
8 Answers
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Why does X[Y] join of data.tables not allow a full outer join, or a left join?
...f a philosophical question about data.table join syntax. I am finding more and more uses for data.tables, but still learning...
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What characters are allowed in an email address?
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See RFC 5322: Internet Message Format and, to a lesser extent, RFC 5321: Simple Mail Transfer Protocol.
RFC 822 also covers email addresses, but it deals mostly with its structure:
addr-spec = local-part "@" domain ; global address
local-part ...
How can I profile C++ code running on Linux?
... a profiler, use one of the suggested ones.
However, if you're in a hurry and you can manually interrupt your program under the debugger while it's being subjectively slow, there's a simple way to find performance problems.
Just halt it several times, and each time look at the call stack. If there...
Why shouldn't I use “Hungarian Notation”?
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Most people use Hungarian notation in a wrong way and are getting wrong results.
Read this excellent article by Joel Spolsky: Making Wrong Code Look Wrong.
In short, Hungarian Notation where you prefix your variable names with their type (string) (Systems Hungarian) is ba...
Should I always use a parallel stream when possible?
With Java 8 and lambdas it's easy to iterate over collections as streams, and just as easy to use a parallel stream. Two examples from the docs , the second one using parallelStream:
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Apache Tomcat Not Showing in Eclipse Server Runtime Environments
I have tomcat 5.5 installed, running and verifiable at http://localhost:8080/ . The Tomcat menu option appears in the Eclipse menu bar and I can start and stop Tomcat from there. In Eclipse, it does not show as a Server Runtime Environment in Window - Preferences - Server - Runtime Environments, no...
Why do people say that Ruby is slow? [closed]
I like Ruby on Rails and I use it for all my web development projects. A few years ago there was a lot of talk about Rails being a memory hog and about how it didn't scale very well but these suggestions were put to bed by Gregg Pollack here.
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What is the difference between Amazon S3 and Amazon EC2 instance?
I need to create a web application using php mysql and html. The no.of requests and data will be very high. I need Amazon server space.
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Why do we use Base64?
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Your first mistake is thinking that ASCII encoding and Base64 encoding are interchangeable. They are not. They are used for different purposes.
When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes.
When you encode data in Base64,...