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How should I have explained the difference between an Interface and an Abstract class?
...rviews, I have been asked to explain the difference between an Interface and an Abstract class .
30 Answers
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Check number of arguments passed to a Bash script
...
Just like any other simple command, [ ... ] or test requires spaces between its arguments.
if [ "$#" -ne 1 ]; then
echo "Illegal number of parameters"
fi
Or
if test "$#" -ne 1; then
echo "Illegal number of parameters"
fi
Suggestions
When in Bash,...
Call a Server-side Method on a Resource in a RESTful Way
Keep in mind I have a rudimentary understanding of REST. Let's say I have this URL:
8 Answers
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Boolean operators && and ||
According to the R language definition , the difference between & and && (correspondingly | and || ) is that the former is vectorized while the latter is not.
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How to iterate over arguments in a Bash script
I have a complex command that I'd like to make a shell/bash script of. I can write it in terms of $1 easily:
8 Answers
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Common programming mistakes for Clojure developers to avoid [closed]
What are some common mistakes made by Clojure developers, and how can we avoid them?
8 Answers
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calculating the difference in months between two dates
... figure out a formula for total months difference. Variable days per month and leap years keep throwing me off. How can I get TotalMonths ?
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Adding a column to a data.frame
...xt, [[.data.frame.
Data frames can be indexed in several modes. When [ and [[ are used with a single vector index (x[i] or x[[i]]), they index the data frame as if it were a list.
my.dataframe["new.col"] <- a.vector
my.dataframe[["new.col"]] <- a.vector
The data.frame method for $, ...
Circle line-segment collision detection algorithm?
I have a line from A to B and a circle positioned at C with the radius R.
27 Answers
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Python loop that also accesses previous and next values
How can I iterate over a list of objects, accessing the previous, current, and next items? Like this C/C++ code, in Python?
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