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Convert string to a variable name
...reg mentioned, assign to assign the variables.
original_string <- c("x=123", "y=456")
pairs <- strsplit(original_string, "=")
lapply(pairs, function(x) assign(x[1], as.numeric(x[2]), envir = globalenv()))
ls()
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What's your most controversial programming opinion?
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Programmers who don't code in their spare time for fun will never become as good as those that do.
I think even the smartest and most talented people will never become truly good programmers unless they treat it as more than a job. Meaning that they do little projects on the...
C++ “virtual” keyword for functions in derived classes. Is it necessary?
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The 'virtualness' of a function is propagated implicitly, however at least one compiler I use will generate a warning if the virtual keyword is not used explicitly, so you may want to use it if only to keep the compiler quiet.
From a purely stylis...
Printing the last column of a line in a file
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Using Perl
$ cat rayne.txt
A1 123 456
B1 234 567
C1 345 678
A1 098 766
B1 987 6545
C1 876 5434
$ perl -lane ' /A1/ and $x=$F[2] ; END { print "$x" } ' rayne.txt
766
$
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How do I parse a URL query parameters, in Javascript? [duplicate]
...ter for the first one). For your example, the above would result in:
{v: "123", p: "hello"}
Here's a working example.
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Can code that is valid in both C and C++ produce different behavior when compiled in each language?
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Here is an example that takes advantage of the difference between function calls and object declarations in C and C++, as well as the fact that C90 allows the calling of undeclared functions:
#include <stdio.h>
struct f { int x; };
int main() {
f();
}
int f() {
return prin...
How can I import a database with MySQL from terminal?
...ple:
mysql -u root -p wp_users < wp_users.sql
mysql -u root -pPassword123 wp_users < wp_users.sql
See also:
4.5.1.5. Executing SQL Statements from a Text File
Note: If you are on windows then you will have to cd (change directory) to your MySQL/bin directory inside the CMD before exec...
How to output a multiline string in Bash?
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Not great if you need this in a function because you'll either need to 1) outdent the string all the way to the left of your file or 2) keep it indented to line up with the rest of your code but then it prints with the indents as well
–...
How to generate keyboard events in Python?
....com/questions/281133/controlling-the-mouse-from-python-in-os-x
# and from https://developer.apple.com/library/mac/documentation/Carbon/Reference/QuartzEventServicesRef/index.html#//apple_ref/c/func/CGEventCreateKeyboardEvent
def KeyDown(k):
keyCode, shiftKey = toKeyCode(k)
time.sleep(0.0...
Site does not exist error for a2ensite
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$ sudo a2ensite mywebsite.conf
5) Check the website on browser and have fun! :)
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