4.3.2 reverse 一個雜湊

%all=(

"t111222333" => "王大空",

"s444555666" => "李小二",

"k333111555" => "陳大一"

);

%bll=reverse %all;

此時，%bll=(

 "王大空" => "t111222333",

 "李小二" => "s444555666",

 "陳大一" => "k333111555",
);