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How to check if an array value exists?
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You could use the PHP in_array function
if( in_array( "bla" ,$yourarray ) )
{
echo "has bla";
}
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How to force R to use a specified factor level as reference in a regression?
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See the relevel() function. Here is an example:
set.seed(123)
x <- rnorm(100)
DF <- data.frame(x = x,
y = 4 + (1.5*x) + rnorm(100, sd = 2),
b = gl(5, 20))
head(DF)
str(DF)
m1 <- lm(y ~ x + b, data = DF)
summary(m1)
Now alter the factor ...
Get the first element of an array
... a array "copy" is needed:
array_shift(array_slice($array, 0, 1));
With PHP 5.4+ (but might cause an index error if empty):
array_values($array)[0];
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PHP code to remove everything but numbers
....new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f6604455%2fphp-code-to-remove-everything-but-numbers%23new-answer', 'question_page');
}
);
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How to get a list of installed android applications and pick one to run
...ng with a server. Is there any guidelines?
– dowjones123
Jun 30 '15 at 20:07
1
@dowjones123 Did u...
In where shall I use isset() and !empty()
...riables and not just values, so isset("foobar") will raise an error. As of PHP 5.5, empty supports both variables and expressions.
So your first question should rather be if isset returns true for a variable that holds an empty string. And the answer is:
$var = "";
var_dump(isset($var));
The typ...
Force SSL/https using .htaccess and mod_rewrite
... can I force to SSL/https using .htaccess and mod_rewrite page specific in PHP.
9 Answers
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Get original URL referer with PHP?
...%2fstackoverflow.com%2fquestions%2f1864583%2fget-original-url-referer-with-php%23new-answer', 'question_page');
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整合phpcms v9和discuz X3.2实现同步登陆、退出免激活 - 更多技术 - 清泛网...
整合phpcms v9和discuz X3.2实现同步登陆、退出免激活内容管理选择了phpcms v9，社区论坛选择了discuz X3 2，现在需要实现两个系统的同步注册、登陆、退出。discuz所属康盛公司为我们提供了解决方案，那就是通过UCenter实现多系统间通...
How to check for null in Twig?
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In addition, unlike the PHP isset() function, is defined will return true if a variable is defined and it's value is null.
– Pavel Petrov
Sep 19 '17 at 7:59
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