PHP – atanh() Function
The PHP atanh() function returns the inverse hyperbolic tangent of a number.
The PHP base_convert() function converts a number from one number base to another.
The PHP cal_days_in_month() function returns the number of days in a month for a specified year and calendar.
The PHP cal_from_jd() function converts a Julian Day Count into a date of a specified calendar.
The PHP cal_info() function returns information about a specified calendar, or all calendars If the calendar parameter is omitted.
The PHP cal_to_jd() function converts a date in a specified calendar to Julian Day Count.
The PHP ceil() function rounds a number up to the nearest integer if necessary.
The PHP checkdate() function is used to check if a Gregorian date is valid.
The PHP checkdnsrr() function checks DNS records for type corresponding to host, and can be used to check our DNS record to verify a domain’s existence.
The PHP chroot() function changes the root directory of the current process to directory, and changes the current working directory to “/”.
The PHP compact() function creates an array from variables and their values. Any strings that does not match variable names will be skipped.