PHP several functions

Pack: Data is loaded into a binary string

Http_build_query: Converts an array to the form of a URL get parameter.

Get_class: Returns the class name of the object, note: Even if called in the parent class method, the class name of the child class is returned.

Get_parent_class: Returns the parent class name of the object or class.

Call_user_func: Invokes the user-defined function provided by the first parameter.

Ob_start: Turn on the output control buffer.

Ob_implicit_flush: Turn absolute swipe on/off, this function forces the output to be sent to the browser whenever there is an output. This does not require each output (echo) to be sent to the browser with flush ().

Ob_get_clean: Gets the contents of the current buffer and deletes the current output ease.

Array_walk_recursive: The user function is applied recursively to each member of the array.

Array_combine: Creates an array with the value of an array as its key name, and the value of the other array as its value.

Array_map-the callback function to the cell of the given array