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<?php function isJson($string) { $decoded = json_decode($string); return (json_last_error() == JSON_ERROR_NONE); } if ( isJson(123) ) { echo "valid JSON"; } else { echo "not valid JSON"; }
Output for 5.4.1, 7.1.25 - 7.1.33, 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
valid JSON
Output for 5.2.0
Fatal error: Call to undefined function json_last_error() in /in/UCpb0 on line 5
Process exited with code 255.
Output for 5.0.5
Fatal error: Call to undefined function json_decode() in /in/UCpb0 on line 4
Process exited with code 255.
Output for 4.4.3
Fatal error: Call to undefined function: json_decode() in /in/UCpb0 on line 4
Process exited with code 255.
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185.49 ms | 401 KiB | 187 Q