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How do I convert a PDF document to a preview image in PHP? [closed]
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10 Answers
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Check if a number has a decimal place/is a whole number
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Check variable equality against a list of values
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Curly braces in string in PHP
...echo "This is ${great}";
// Works
echo "This square is {$square->width}00 centimeters broad.";
// Works, quoted keys only work using the curly brace syntax
echo "This works: {$arr['key']}";
// Works
echo "This works: {$arr[4][3]}";
// This is wrong for the same reason as $foo[bar] is wrong...
Extract a regular expression match
...nd adds a few that are missing:
library(stringr)
str_locate("aaa12xxx", "[0-9]+")
# start end
# [1,] 4 5
str_extract("aaa12xxx", "[0-9]+")
# [1] "12"
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Symbol for any number of any characters in regex?
...ace or any non-whitespace) as many times as possible down to and including 0.
[\s\S]*
This expression will match as few as possible, but as many as necessary for the rest of the expression.
[\s\S]*?
For example, in this regex [\s\S]*?B will match aB in aBaaaaB. But in this regex [\s\S]*B will...
Compare integer in bash, unary operator expected
... specifying a default value for $i if $i is blank, as follows:
if [ "${i:-0}" -ge 2 ] ; then ...
This will substitute the value 0 instead of $i is $i is undefined. I still maintain the quotes because, again, if $i is a bunch of blanks then it does not count as undefined, it will not be replaced ...
How to get a number of random elements from an array?
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edited Feb 20 '18 at 17:21
answered Oct 9 '13 at 10:52
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Checking for NULL pointer in C/C++ [closed]
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206
In my experience, tests of the form if (ptr) or if (!ptr) are preferred. They do not depend on ...
CSS: transition opacity on mouse-out?
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You're applying transitions only to the :hover pseudo-class, and not to the element itself.
.i...