PHP – gmmktime() Function
The PHP gmmktime() function returns the Unix timestamp for a GMT date.
PHP – gmstrftime() Function
The PHP gmstrftime() function formats a GMT/UTC time and/or date according to locale settings.
PHP – gregoriantojd() Function
The PHP gregoriantojd() function converts a date from the Gregorian Calendar to a Julian Day Count.
PHP – header() Function
The PHP header() function sends a raw HTTP header to a client, and must be called before any actual output is sent.
PHP – header_register_callback() Function
The PHP header_register_callback() function calls a header function to be executed after all PHP headers are sent, and before any other output is sent.
PHP – header_remove() Function
The PHP header_remove() function removes an HTTP header previously set with the header() function.
PHP – headers_list() Function
The PHP headers_list() function returns a list of response headers to be sent to the browser.
PHP – headers_sent() Function
The PHP headers_sent() function checks if/where headers have been sent.
PHP – hexdec() Function
The PHP hexdec() function converts a hexadecimal number to a decimal number.
PHP – highlight_file() Function
The PHP highlight_file() function outputs a file with the PHP syntax highlighted. The syntax is highlighted by using HTML tags.
PHP – highlight_string() Function
The PHP highlight_string() function outputs a string with the PHP syntax highlighted. The syntax is highlighted by using HTML tags.
PHP – http_response_code() Function
The PHP http_response_code() function sets or returns the HTTP response status code.
PHP – hypot() Function
The PHP hypot() function calculates the hypotenuse of a right-angle triangle.
PHP – if Keyword
The PHP if keyword is used to create an if conditional. The elseif and else keywords can then be used to run code when the if condition is not met.
PHP – ignore_user_abort() Function
The PHP ignore_user_abort() function sets whether a user should abort a script execution when they disconnect.
PHP – implements Keyword
The PHP implements keyword is used to declare that a class must have the methods described in the specified interface (called polymorphism).