Parsing PHP built-in function compact with code

Read the description of the function compact () in the manual, which describes my understanding of the function in PHP code.

The compact () can accept parameters for variable data, which can be a field string or an array that includes variable names

I understand that the compact () function gets to the variable name, first to determine whether the variable has a reputation (isset (variable)) if it is already known, the variable is pressed into the array

Returns an array of stored variables after all parameters have been traversed

Parsing PHP built-in function compact with code