如果指定的参数之一不是数组，则阻止array_merge合并数组

Question

I want array_merge to merge only when the argument specified is an array else skip that argument.

Below is the code,

<?php

$mergedArray = array();
$a = array('Hello');
$b = array('Hi');
$c = 'World';
$mergedArray = array_merge($mergedArray, $a, $b, $c);
print_r($mergedArray);

?>

For the above code, I get a warning that $c is not an array. I know that converting it into an array will fix the issue,

$mergedArray = array_merge($mergedArray, $a, $b, (array)$c);

But, $c can be an array or a string, and if it a string I don't want to include it as a parameter in my array_merge, if it an array I want it to be included. Is there any direct method in php to do it, or do I need to write it in if-else statement.

EDIT: It doesn't make a difference if I include an empty array by checking is_array($c). But if I have to implode that result using a delimiter then it will cause an issue,

Modified code,

<?php

$mergedArray = array();
$a = array('Hello');
$b = array('Hi');
$c = 'World';
$mergedArray = array_merge($mergedArray, $a, $b, is_array($c) ? $c : []);
$result = implode(' | ', $mergedArray);
print_r($mergedArray);

?>

Now for the above code, in case of an empty array, I will get | at the end of $result which I don't want.

Answer 1

Use is_array function to check if a variable is an array or not.

$mergedArray = array_merge($mergedArray, $a, $b, is_array($c) ? $c : array());

If $c is an array, combine it. If not, just combine with empty array which doesn't affect the result.