void unDefine(string name1[, string name2...]);

namex - the list of variable names to remove from memory

After this function is used on a variable, such as name1, isDefined("name1") will again return 0. Accesses to the variable name will fail because it will no longer exist.

If a variable name in the list is already undefined, then the function has no effect on the undefined variable name.

Example: To remove a variable named varname from memory, use unDefine("varname"), do not use unDefine($varname).

NOTE: This function is deprecated; use unset() instead.