?????? ?????

????????ж?
?????????
  1??while???
  2??until???
  3??for???
  4??????б?(????)???????foreach???
   5??do???
  6?????????
  7???????goto???
????????????

????????ж?
  if ( <expression>) {
    <statement_block_1>
  }
  elsif ( <expression> ) {
    <statement_block_2>
  }
  ...
  else{
    <statement_block_3>
  }
?????????
1??while???
  while ( <expression> ) {
    <statement_block>
  }
2??until???
  until ( <expression> ) {
    <statement_block>
  }
3????C??for??? ????
  for ($count=1; $count <= 5; $count++) {
    # statements inside the loop go here
  }
????????for???????????????????????
  for ($line = <STDIN>, $count = 1; $count <= 3;   $line = <STDIN>, $count++) {
    print ($line);
  }
??????????????
  $line = <STDIN>;
  $count = 1;
  while ($count <= 3) {
    print ($line);
    $line = <STDIN>;
    $count++;
  }
4??????б?(????)????????????foreach?? ?????
  foreach localvar (listexpr) {
    statement_block;
  }
????
  foreach $word (@words) {
    if ($word eq "the") {
      print ("found the word 'the'\n");
    }
  }
???
(1)????????????localvar?????????????????????????????????????????????
(2)??????и????????????????????????????磺
  @list = (1, 2, 3, 4, 5);
  foreach $temp (@list) {
    if ($temp == 2) {
      $temp = 20;
    }
  }
???@list??????(1, 20, 3, 4, 5)??
5??do???
  do {
    statement_block
  } while_or_until (condexpr);
  do??????????????????
6?????????
  ???????last????C?е?break?????????????????????next????C?е?continue?????????PERL???е??????????redo???京?????????????????????????????????????????????redo??????do????в??????á?
7???????goto label;???

????????????
  ???statement keyword condexpr??????keyword???if??unless??while??until???磺
    print ("This is zero.\n") if ($var == 0);
    print ("This is zero.\n") unless ($var != 0);
    print ("Not zero yet.\n") while ($var-- > 0);
    print ("Not zero yet.\n") until ($var-- == 0);
  ????????ж?д????棬?????????е??

????? ????? ??

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