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What text editor is available in Heroku bash shell? [closed]
I'm trying to update httpd.conf in my Cedar-based Heroku app. I got to my Heroku bash with
15 Answers
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@try - catch block in Objective-C
Why doesn't @try block work?
It crashed the app, but it was supposed to be caught by the @try block.
3 Answers
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Determine the data types of a data frame's columns
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Your best bet to start is to use ?str(). To explore some examples, let's make some data:
set.seed(3221) # this makes the example exactly reproducible
my.data <- data.frame(y=rnorm(5),
x1=c(1:5),
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Writing files in Node.js
I've been trying to find a way to write to a file when using Node.js, but with no success. How can I do that?
19 Answers
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(this == null) in C#!
Due to a bug that was fixed in C# 4, the following program prints true . (Try it in LINQPad)
6 Answers
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jQuery SVG, why can't I addClass?
I am using jQuery SVG. I can't add or remove a class to an object. Anyone know my mistake?
15 Answers
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Browse and display files in a git repo without cloning
Is there a way to browse and display files in a git repo without cloning it first? I can do those in svn using the commands:
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How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?
...ike to write a single SQL command to drop multiple columns from a single table in one ALTER TABLE statement.
11 Answers
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How to validate an email address using a regular expression?
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The fully RFC 822 compliant regex is inefficient and obscure because of its length. Fortunately, RFC 822 was superseded twice and the current specification for email addresses is RFC 5322. RFC 5322 leads to a regex that can be understood if studied for a few minutes and is eff...
What does the “map” method do in Ruby?
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The map method takes an enumerable object and a block, and runs the block for each element, outputting each returned value from the block (the original object is unchanged unless you use map!):
[1, 2, 3].map { |n| n * n } #=> [1, 4, 9]
Array and Rang...