检查数组是否为数字的最佳方法

Question

Say i have a one dimensional array of 500,000 cells and I want to know if this array is numeric, the most obvious options are either to iterate on the whole array and use the is_numeric() function or to use an array_shift. The problem with that is that both of these options are O(n) (correct me if I'm wrong) and will be more expensive as the data in the array grow. I'm thinking of another way but I'm not sure of its O, which is to search for all the non numeric values in the array using regex and array_search. What do you think and are there any less expensive options?

Answer 1

Would implode be efficient? If you have a simple array, I would join all the elements together into a string and run it against is_numeric. At least you would only have to do the numeric check once.

$foo = array(1, 2, 3, 4, 5, 6, ....);
$bar = implode('', $foo);

var_dump(is_numeric($bar));