使用array_rand PHP的未定义索引

Question

I am trying to re-create an array by choosing random elements of an existing array using array_rand().

However, when using the following code and spitting out the array, I am getting an undefined index error in reference to it.

The array is $city_users_trimmed.

PHP code:

$rand = array_rand($city_users_trimmed, 1);

$data = array($city_users_trimmed[$rand[0]]);

I know that $city_users_trimmed has at least 1 element in it, so there is no reason I see why this wouldn't be working.

I tested it by running:

$data = array($city_users_trimmed[0]);

which works, so there is at least one element in the $city_users_trimmed array. Is there anything you see that is causing this issue? Thank you.

Answer 1

Check http://php.net/manual/en/function.array-rand.php

When picking only one entry, array_rand() returns the key for a random entry. Otherwise, an array of keys for the random entries is returned.

So in $rand is your key, not in $rand[0]