Online PHP editor | output for 3A3Eg

@ 2021-01-11T00:02:50Z

<?php

function is_cyclic(array &$array) {
    json_encode($array);
    return json_last_error() === JSON_ERROR_RECURSION;
}

$array = [1, [2, 3]];
$array[1][1] = &$array;
var_dump(is_cyclic($array));

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