如何将数组的所有元素（未知长度）作为单独的参数传递给函数？ [重复]

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• How to bind mysqli bind_param arguments dynamically in PHP? 6 answers

I have an array in PHP which may contain data such as this:

$data = array("Apples", "Oranges", "Grapes", "Pears");

I then want to pass these values into the mysqli bind_param function. For this example it would look like this:

$stmt->bind_param("ssss", $data[0], $data[1], $data[2], $data[3]);

My question is how can I produce the same results as above if the length of the array is unknown? For example it may be five, ten or 15 elements long.

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Answer 1

With PHP 5.6 or higher:

$stmt->bind_param(str_repeat("s", count($data)), ...$data);

With PHP 5.5 or lower you might (and I did) expect the following to work:

call_user_func_array(
    array($stmt, "bind_param"),
    array_merge(array(str_repeat("s", count($data))), $data));

...but mysqli_stmt::bind_param expects its parameters to be references whereas this passes a list of values (thanks Barmar for pointing this out).

You can work around this (although it's an ugly workaround) by first creating an array of references to the original array.

$references_to_data = array();
foreach ($data as &$reference) { $references_to_data[] = &$reference; }
unset($reference);
call_user_func_array(
    array($stmt, "bind_param"),
    array_merge(array(str_repeat("s", count($data))), $references_to_data));