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<?php $arr = [1,2,3]; var_dump(memory_get_usage()); foreach ($arr as $k => $v) { var_dump(memory_get_usage()); if (!isset($arr[$k])) { var_dump(memory_get_usage()); } } var_dump(key($arr));
Output for 7.3.0 - 7.3.1
int(388216) int(388248) int(388248) int(388248) int(0)
Output for 7.2.0 - 7.2.13
int(384240) int(384272) int(384272) int(384272) int(0)
Output for 7.1.0 - 7.1.25
int(347568) int(347600) int(347600) int(347600) int(0)
Output for 7.0.0 - 7.0.33
int(347944) int(347976) int(347976) int(347976) int(0)
Output for 5.6.0 - 5.6.38
int(218880) int(219152) int(219152) int(219152) NULL
Output for 5.5.0 - 5.5.38
int(218880) int(219136) int(219136) int(219136) NULL
Output for 5.4.10 - 5.4.45
int(219400) int(219656) int(219656) int(219656) NULL
Output for 5.4.0 - 5.4.9
int(218872) int(219128) int(219128) int(219128) NULL
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/0nHqk on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected '[' in /in/0nHqk on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/0nHqk on line 3
Process exited with code 255.

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