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PHP Superglobals
Superglobals $GLOBALS $_SERVER $_REQUEST $_POST $_GET

PHP Forms

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PHP Advanced

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PHP OOP

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MySQL Database

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PHP XML

PHP XML Parsers PHP SimpleXML Parser PHP SimpleXML - Get PHP XML Expat PHP XML DOM

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PHP Reference

PHP Overview PHP Array
array() array_change_key_case() array_chunk() array_column() array_combine() array_count_values() array_diff() array_diff_assoc() array_diff_key() array_diff_uassoc() array_diff_ukey() array_fill() array_fill_keys() array_filter() array_flip() array_intersect() array_intersect_assoc() array_intersect_key() array_intersect_uassoc() array_intersect_ukey() array_key_exists() array_keys() array_map() array_merge() array_merge_recursive() array_multisort() array_pad() array_pop() array_product() array_push() array_rand() array_reduce() array_replace() array_replace_recursive() array_reverse() array_search() array_shift() array_slice() array_splice() array_sum() array_udiff() array_udiff_assoc() array_udiff_uassoc() array_uintersect() array_uintersect_assoc() array_uintersect_uassoc() array_unique() array_unshift() array_values() array_walk() array_walk_recursive() arsort() asort() compact() count() current() each() end() extract() in_array() key() krsort() ksort() list() natcasesort() natsort() next() pos() prev() range() reset() rsort() shuffle() sizeof() sort() uasort() uksort() usort()
PHP Calendar
cal_days_in_month() cal_from_jd() cal_info() cal_to_jd() easter_date() easter_days() frenchtojd() gregoriantojd() jddayofweek() jdmonthname() jdtofrench() jdtogregorian() jdtojewish() jdtojulian() jdtounix() jewishtojd() juliantojd() unixtojd()
PHP Date
checkdate() date_add() date_create_from_format() date_create() date_date_set() date_default_timezone_get() date_default_timezone_set() date_diff() date_format() date_get_last_errors() date_interval_create_from_date_string() date_interval_format() date_isodate_set() date_modify() date_offset_get() date_parse_from_format() date_parse() date_sub() date_sun_info() date_sunrise() date_sunset() date_time_set() date_timestamp_get() date_timestamp_set() date_timezone_get() date_timezone_set() date() getdate() gettimeofday() gmdate() gmmktime() gmstrftimee() idate() localtime() microtime() mktime() strftime() strptime() strtotime() time() timezone_abbreviations_list() timezone_identifiers_list() timezone_location_get() timezone_name_from_abbr() timezone_name_get() timezone_offset_get() timezone_open() timezone_transitions_get() timezone_version_get()
PHP Directory
chdir() chroot() closedir() dir() getcwd() opendir() readdir() rewinddir() scandir()
PHP Error
debug_backtrace() debug_print_backtrace() error_get_last() error_log() error_reporting() restore_error_handler() restore_exception_handler() set_error_handler() set_exception_handler() trigger_error()
PHP Filesystem
basename() chgrp() chmod() chown() clearstatcache() copy() delete() dirname() disk_free_space() disk_total_space() diskfreespace() fclose() feof() fflush() fgetc() fgetcsv() fgets() fgetss() file() file_exists() file_get_contents() file_put_contents() fileatime() filectime() filegroup() fileinode() filemtime() fileowner() fileperms() filesize() filetype() flock() fnmatch() fopen() fpassthru() fputcsv() fputs() fread() fscanf() fseek() fstat() ftell() ftruncate() fwrite() glob() is_dir() is_executable() is_file() is_link() is_readable() is_uploaded_file() is_writable() is_writeable() lchgrp() lchown() link() linkinfo() lstat() mkdir() move_uploaded_file() parse_ini_file() parse_ini_string() pathinfo() pclose() popen() readfile() readlink() realpath() realpath_cache_get() realpath_cache_size() rename() rewind() rmdir() set_file_buffer() stat() symlink() tempnam() tmpfile() touch() umask() unlink()
PHP Filter
filter_has_var() filter_id() filter_input() filter_input_array() filter_list() filter_var() filter_var_array()
PHP FTP
ftp_alloc() ftp_cdup() ftp_chdir() ftp_chmod() ftp_close() ftp_connect() ftp_delete() ftp_exec() ftp_fget() ftp_fput() ftp_get() ftp_get_option() ftp_login() ftp_mdtm() ftp_mkdir() ftp_mlsd() ftp_nb_continue() ftp_nb_fget() ftp_nb_fput() ftp_nb_get() ftp_nb_put() ftp_nlist() ftp_pasv() ftp_put() ftp_pwd() ftp_quit() ftp_raw() ftp_rawlist() ftp_rename() ftp_rmdir() ftp_set_option() ftp_site() ftp_size() ftp_ssl_connect() ftp_systype()
PHP JSON
json_decode() json_encode()
PHP Libxml
libxml_clear_errors() libxml_disable_entity_loader() libxml_get_errors() libxml_get_last_error() libxml_set_external_entity_loader() libxml_set_streams_context() libxml_use_internal_errors()
PHP Mail
ezmlm_hash() mail()
PHP Math
abs() acos() acosh() asin() asinh() atan() atan2() atanh() base_convert() bindec() ceil() cos() cosh() decbin() dechex() decoct() deg2rad() exp() expm1() floor() fmod() getrandmax() hexdec() hypot() intdiv() is_finite() is_infinite() is_nan() lcg_value() log() log10() log1p() max() min() mt_getrandmax() mt_rand() mt_srand() octdec() pi() pow() rad2deg() rand() round() sin() sinh() sqrt() srand() tan() tanh()
PHP Misc
connection_aborted() connection_status() connection_timeout() constant() define() defined() die() eval() exit() get_browser() __halt_compiler() highlight_file() highlight_string() hrtime() ignore_user_abort() pack() php_strip_whitespace() show_source() sleep() sys_getloadavg() time_nanosleep() time_sleep_until() uniqid() unpack() usleep()
PHP MySQLi
affected_rows autocommit change_user character_set_name close commit connect connect_errno connect_error data_seek debug dump_debug_info errno error error_list fetch_all fetch_array fetch_assoc fetch_field fetch_field_direct fetch_fields fetch_lengths fetch_object fetch_row field_count field_seek get_charset get_client_info get_client_stats get_client_version get_connection_stats get_host_info get_proto_info get_server_info get_server_version info init insert_id kill more_results multi_query next_result options ping poll prepare query real_connect real_escape_string real_query reap_async_query refresh rollback select_db set_charset set_local_infile_handler sqlstate ssl_set stat stmt_init thread_id thread_safe use_result warning_count
PHP Network
checkdnsrr() closelog() dns_check_record() dns_get_mx() dns_get_record() fsockopen() gethostbyaddr() gethostbyname() gethostbynamel() gethostname() getmxrr() getprotobyname() getprotobynumber() getservbyname() getservbyport() header_register_callback() header_remove() header() headers_list() headers_sent() http_response_code() inet_ntop() inet_pton() ip2long() long2ip() openlog() pfsockopen() setcookie() setrawcookie() socket_get_status() socket_set_blocking() socket_set_timeout() syslog()
PHP SimpleXML
__construct() __tostring() addAttribute() addChild() asXML() attributes() children() count() getDocNamespaces() getName() getNamespaces() registerXPathNamespace() saveXML() simplexml_import_dom() simplexml_load_file() simplexml_load_string() xpath()
current() getchildren() haschildren() key() next() rewind() valid()
PHP Stream PHP String
addcslashes() addslashes() bin2hex() chop() chr() chunk_split() convert_cyr_string() convert_uudecode() convert_uuencode() count_chars() crc32() crypt() echo() explode() fprint() get_html_translation_table() hebrev() hebrevc() hex2bin() html_entity_decode() htmlentities() htmlspecialchars_decode() htmlspecialchars() implode() join() lcfirst() levenshtein() localeconv() ltrim() md5() md5_file() metaphone() money_format() nl_langinfo() nl2br() number_format() ord() parse_str() print() printf() quoted_printable_decode() quoted_printable_encode() quotemeta() rtrim() setlocale() sha1() sha1_file() similar_text() soundex() sprintf() sscanf() str_getcsv() str_ireplace() str_pad() str_repeat() str_replace() str_rot13() str_shuffle() str_split() str_word_count() strcasecmp() strchr() strcmp() strcoll() strcspn() strip_tags() stripcslashes() stripslashes() stripos() stristr() strlen() strnatcasecmp() strnatcmp() strncasecmp() strncmp() strpbrk() strpos() strrchr() strrev() strripos() strrpos() strspn() strstr() strtok() strtolower() strtoupper() strtr() substr() substr_compare() substr_count() substr_replace() trim() ucfirst() ucwords() vfprintf() vprintf() vsprintf() wordwrap()
PHP Variable Handling
boolval() debug_zval_dump() doubleval() is_countable() empty() floatval() get_defined_vars() get_resource_type() gettype() intval() is_array() is_bool() is_callable() is_double() is_float() is_int() is_integer() is_iterable() is_long() is_null() is_numeric() is_object() is_real() is_resource() is_scalar() is_string() isset() print_r() serialize() settype() strval() unserialize() unset() var_dump() var_export()
PHP XML Parser
utf8_decode() utf8_encode() xml_error_string() xml_get_current_byte_index() xml_get_current_column_number() xml_get_current_line_number() xml_get_error_code() xml_parse() xml_parse_into_struct() xml_parser_create_ns() xml_parser_create() xml_parser_free() xml_parser_get_option() xml_parser_set_option() xml_set_character_data_handler() xml_set_default_handler() xml_set_element_handler() xml_set_end_namespace_decl_handler() xml_set_external_entity_ref_handler() xml_set_notation_decl_handler() xml_set_object() xml_set_processing_instruction_handler() xml_set_start_namespace_decl_handler() xml_set_unparsed_entity_decl_handler()
PHP Zip
zip_close() zip_entry_close() zip_entry_compressedsize() zip_entry_compressionmethod() zip_entry_filesize() zip_entry_name() zip_entry_open() zip_entry_read() zip_open() zip_read()
PHP Timezones

PHP srand() Function

❮ PHP Math Reference

Example

Seed the random number generator:

<?php
srand(mktime());
echo(rand());
?>
Try it Yourself »

Definition and Usage

The srand() function seeds the random number generator (rand()).

Tip: From PHP 4.2.0, the random number generator is seeded automatically and there is no need to use this function.

Syntax

srand(seed);

Parameter Values

Parameter Description
seed Optional. Specifies the seed value

Technical Details

Return Value: None
Return Type: -
PHP Version: 4+
PHP Changelog: PHP 7.1.0: srand() has been an alias of mt_srand().
PHP 4.2.0: Random number generator is now seeded automatically.
❮ PHP Math Reference