usleep() function delays code execution for a number of microseconds.
unpack() function unpacks data from a binary string.
The uniqid() function generates a unique ID based on the current time in microseconds.
time_sleep_until() function delays code execution until the specified time.
The time_nanosleep() function, a commonly used function in PHP5, delays code execution for a number of seconds and nanoseconds.
sleep() function delays code execution for a few seconds.
The show_source() function performs syntax highlighting on files.
The strip_whitespace() function returns the source code file with PHP comments and whitespace characters removed.
The pack() function loads data into a binary string.
ignore_user_abort() function sets whether disconnecting from the client will terminate the execution of the script.
highlight_string() function performs syntax highlighting on strings.
The highlight_file() function performs syntax highlighting on files.
The get_browser() function, a commonly used function in PHP5, returns the performance of the user's browser.
exit() function outputs a message and exits the current script.
eval() function evaluates string according to PHP code.
die() function outputs a message and exits the current script.
defined() function checks whether a constant exists.
define() function defines a constant.
constant() function returns the value of a constant.
The connection_status() function, a commonly used function in PHP5, returns the current connection status.
The connection_aborted() function checks whether the client is disconnected.
zip_read() function reads the next file in the opened zip archive.
The zip_open() function opens a ZIP file for reading.
The zip_entry_read() function gets the contents from an open zip archive entry.
The zip_entry_open() function opens a ZIP archive entry for reading.
The zip_entry_name() function, a commonly used function in PHP5, returns the name of the zip file item.
The zip_entry_filesize() function returns the original size of the zip archive entry (before compression).
The zip_entry_compressionmethod() function returns the compression method of the zip archive entry.
The zip_entry_compressedsize() function returns the compressed file size of the zip archive entry.
The zip_entry_close() function closes the zip archive file opened by the zip_entry_open() function.
The zip_close() function closes the zip archive file opened by the zip_open() function.
xml_set_unparsed_entity_decl_handler() function specifies the function to be called when an unresolved entity name (NDATA) declaration is encountered.
The xml_set_processing_instruction_handler() function specifies the function to be called when the parser finds a processing instruction in the XML document.
The xml_set_object() function allows using XML parsers with objects.
The xml_set_notation_decl_handler() function of PHP5 commonly used functions specifies the function to be called when the parser finds a symbol declaration in the XML document.
The xml_set_external_entity_ref_handler() function specifies the function that is called when the parser finds an external entity in the XML document.
xml_set_element_handler() function establishes the starting and ending element handlers.
The xml_set_default_handler() function establishes the default data handler for the XML parser.
xml_set_character_data_handler() function creates a character data handler.
The xml_parser_set_option() function sets options for the XML parser.
The xml_parser_get_option() function gets option setting information from the XML parser.
xml_parser_free() function frees the XML parser.
The xml_parser_create() function, a commonly used function in PHP5, creates an XML parser.
xml_parser_create_ns() function creates an XML parser with namespace support.
xml_parse_into_struct() function parses XML data into an array.
xml_parse() function parses XML documents.
xml_get_error_code() function gets the XML parser error code.
xml_get_current_line_number() function gets the current line number of the XML parser.
xml_get_current_column_number() function gets the current column number of the XML parser.
The xml_get_current_byte_index() function, a commonly used function in PHP5, obtains the current byte index of the XML parser.
xml_error_string() function gets the error description of the XML parser.
utf8_encode() function encodes ISO-8859-1 string to UTF-8.
utf8_decode() function decodes UTF-8 string to ISO-8859-1.
The wordwrap() function wraps the string according to the specified length.
The vsprintf() function writes the formatted string into a variable.
vprintf() function outputs a formatted string.
The vfprintf() function writes a formatted string to the specified output stream.
The ucwords() function, a commonly used function in PHP5, converts the first character of each word in the string to uppercase.
ucfirst() function converts the first character in a string to uppercase.
trim() function removes whitespace characters and other predefined characters from both ends of a string.
substr_replace() function replaces part of a string with another string.
substr_count() function counts the number of times a substring appears in a string.
substr_compare() function compares two strings starting from the specified length.
substr() function returns a part of a string.
strtr() function converts specific characters in a string.
strtoupper() function converts a string to uppercase.
strtolower() function converts a string to lowercase.
The strtok() function, a commonly used function in PHP5, splits a string into smaller strings.
strstr() function searches for the first occurrence of a string within another string.
strspn() function returns the number of specific characters contained in a string.
strrpos() function finds the last occurrence of a string within another string.
strripos() function finds the last occurrence of a string within another string.
strrev() function reverses a string.
strrchr() function finds the last occurrence of a string within another string and returns all characters from that position to the end of the string.
strpos() function returns the position of the first occurrence of a string within another string.
Strpbrk() function, a commonly used function in PHP5, searches for any one of the specified characters in a string.
strncmp() function compares two strings.
strncasecmp() function compares two strings.
The strnatcmp() function uses a "natural" algorithm to compare two strings.
The strnatcasecmp() function uses a "natural" algorithm to compare two strings.
strlen() function returns the length of the string.
stristr() function finds the first occurrence of a string within another string.
stripos() function returns the position of the first occurrence of a string within another string.
The stripslashes() function removes the backslashes added by the addslashes() function.
The stripcslashes() function removes backslashes added by the addcslashes() function.
strip_tags() function strips HTML, XML and PHP tags.
strcspn() function returns the number of characters searched in a string before any specified character is found.
Strcoll() function, a commonly used function in PHP5, compares two strings.
strcmp() function compares two strings.
strchr() function searches for the first occurrence of a string within another string.
strcasecmp() function compares two strings.
str_word_count() function counts the number of words in a string.
str_split() function splits a string into an array.
str_shuffle() function randomly shuffles all characters in a string.
str_rot13() function performs ROT13 encoding on a string.
str_replace() function uses a string to replace other characters in a string.
str_repeat() function repeats a string a specified number of times.
str_pad() function pads a string to the specified length.
str_ireplace() function uses a string to replace other characters in a string.
The sscanf() function, a commonly used function in PHP5, parses input from a string according to the specified format.
The sprintf() function writes the formatted string into a variable.
The soundex() function calculates the soundex key of a string.
similar_text() function counts the number of matching characters in two strings.
The sha1_file() function calculates the SHA-1 hash of a file.
The sha1() function computes the SHA-1 hash of a string.
setlocale() function sets regional information (regional information).
PHP5 commonly used functions rtrim() P rtrim() function
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
