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Only variables should be passed by reference
...file_name) cannot be turned into a reference. This is a restriction in the PHP language, that probably exists for simplicity reasons.
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How to write into a file in PHP?
I have this script on one free PHP-supporting server:
9 Answers
9
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How to set my phpmyadmin user session to not time out so quickly? [duplicate]
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To increase the phpMyAdmin Session Timeout, open config.inc.php in the root phpMyAdmin directory and add this setting (anywhere).
$cfg['LoginCookieValidity'] = <your_new_timeout>;
Where <your_new_timeout> is some number larger...
How do I deep copy a DateTime object?
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I haven't tested it actually, but it is mentioned at php.net that this is only aviable for PHP 5.3 and greater.
– hugo der hungrige
Feb 1 '13 at 1:02
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Is there any difference between __DIR__ and dirname(__FILE__) in PHP?
...7)
But, there are at least two differences :
__DIR__ only exists with PHP >= 5.3
which is why dirname(__FILE__) is more widely used
__DIR__ is evaluated at compile-time, while dirname(__FILE__) means a function-call and is evaluated at execution-time
so, __DIR__ is (or, should be) faste...
isset() and empty() - what to use
... $var; (a variable declared, but without a value in a class)
From http://php.net/manual/en/function.empty.php
As mentioned in the comments the lack of warning is also important with empty()
PHP Manual says
empty() is the opposite of (boolean) var, except that no warning is
generated when...
Can an html element have multiple ids?
...answered Apr 16 '11 at 7:53
user123444555621user123444555621
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How do you connect to multiple MySQL databases on a single webpage?
...a few databases and want to put all the information onto one webpage using PHP. I was wondering how I can connect to multiple databases on a single PHP webpage.
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How can I use PHP to dynamically publish an ical file to be read by Google Calendar?
Any Google search on PHP ical just brings up phpicalendar and how to parse or read IN ical files. I just want to write a PHP file that pulls events from my database and writes them out in ical format.
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Remove duplicated rows using dplyr
...ction for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_nu...