目录
- PHP Tutorial
- PHP Forms
- PHP Advanced
- PHP OOP
- MySQL Database
- PHP XML
- PHP - AJAX
- PHP Examples
-
PHP Reference
- PHP Overview
-
PHP Array
- 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
-
PHP Date
- 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()
- gmstrftime()
- 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
- PHP Error
- PHP Exception
-
PHP Filesystem
- 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
-
PHP FTP
- 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
-
PHP Keywords
- PHP Keywords
- abstract
- and
- as
- break
- callable
- case
- catch
- class
- clone
- const
- continue
- declare
- default
- do
- echo
- else
- elseif
- empty
- enddeclare
- endfor
- endforeach
- endif
- endswitch
- extends
- final
- finally
- fn
- for
- foreach
- function
- global
- if
- implements
- include
- include_once
- instanceof
- insteadof
- interface
- isset
- list
- namespace
- new
- or
- private
- protected
- public
- require
- require_once
- return
- static
- switch
- throw
- trait
- try
- use
- var
- while
- xor
- yield
- yield from
- PHP Libxml
- PHP Mail
-
PHP Math
- 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
- 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
- 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
- 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 Output Control
- PHP RegEx
-
PHP SimpleXML
- 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
- 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
- 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
- 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
- PHP Timezones
PHP require_once Keyword
Example
Use require_once to add a footer to a page:
<!DOCTYPE html>
<html>
<body>
<h1>Welcome to my home page!</h1>
<p>Some text.</p>
<p>Some more text.</p>
<?php require_once 'footer.html';?>
</body>
</html>
Definition and Usage
The require_once keyword is used to embed PHP code from another file. If the file is not found, a fatal error is thrown and the program stops. If the file was already included previously, this statement will not include it again.
Related Pages
The require keyword
The include keyword
The include_once keyword
Read more about including files in our PHP Include Files Tutorial.
❮ PHP Keywords
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