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<?php $small_num = '9999'; $large_num = '9999999999999999999999999999999'; $arr = (array)json_decode("{\"$large_num\":\"1\",\"$small_num\":\"1\"}"); var_dump($arr); var_dump(array( 'isset_small_num_key' => isset($arr[$small_num]), 'isset_large_num_key' => isset($arr[$large_num]), ));
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(2) { ["9999999999999999999999999999999"]=> string(1) "1" [9999]=> string(1) "1" } array(2) { ["isset_small_num_key"]=> bool(true) ["isset_large_num_key"]=> bool(true) }
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33
array(2) { ["9999999999999999999999999999999"]=> string(1) "1" ["9999"]=> string(1) "1" } array(2) { ["isset_small_num_key"]=> bool(false) ["isset_large_num_key"]=> bool(true) }

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