$a = 3;
{
    last unless $a == 4;
    redo; # if ( ... );
}

##</code><code>##

do BLOCK
               Not really a function.  Returns the value of the last command in the sequence of commands indicated by BLOCK.  When modified by the "while" or "until" loop modifier, executes the BLOCK
               once before testing the loop condition. (On other statements the loop modifiers test the conditional first.)

               "do BLOCK" does not count as a loop, so the loop control statements "next", "last", or "redo" cannot be used to leave or restart the block.  See [doc://perlsyn] for alternative strategies.