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Date/Time: date , time , mktime , strtotime , DateTime , DateInterval , add , sub, diff, format, setTimestamp , setTime , setDate
Mathematical: round , ceil , floor , rand , srand , pow , exp , abs , max , min , bindec , hexdec , octdec , base_convert
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Array: explode , implode , is_array , in_array , is_numeric array_diff , array_diff_key, count
JSON: json_decode , json_encode
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cURL: curl_init , curl_setopt , curl_exec , curl_errno , curl_error , curl_getinfo , curl_close , http_build_query
cURL Constants: CURLOPT_URL, CURLOPT_HEADER, CURLOPT_NOBODY, CURLOPT_HTTPGET, CURLOPT_RETURNTRANSFER
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