php 做用域

<?
$data=array(
     0 => array("id"=> "1","newTip" => "0"),  
     1 => array("id"=> "2","newTip" => "0")
     2 => array("id"=> "11","newTip" => "1"),  
     3 => array("id"=> "12","newTip" => "1" ),   
  );  
$newData=array();
foreach($data as $value){
    $tmp=array(); //（1）注掉
    $tmp['id'] = $value['id'];
    if($value['newTip'] == "0"){
        $tmp['newTip'] = $value['newTip'];
    }
    $newData[] = $tmp;
}
var_dump($newData);

輸出：
array(4) {
  [0]=>
  array(2) {
    ["id"]=>
    string(1) "1"
    ["newTip"]=>
    string(1) "0"
  }
  [1]=>
  array(2) {
    ["id"]=>
    string(1) "2"
    ["newTip"]=>
    string(1) "0"
  }
  [2]=>
  array(1) {
    ["id"]=>
    string(2) "11"
  }
  [3]=>
  array(1) {
    ["id"]=>
    string(2) "12"
  }
}

若是（1）注掉
array(4) {
  [0]=>
  array(2) {
    ["id"]=>
    string(1) "1"
    ["newTip"]=>
    string(1) "0"
  }
  [1]=>
  array(2) {
    ["id"]=>
    string(1) "2"
    ["newTip"]=>
    string(1) "0"
  }
  [2]=>
  array(2) {
    ["id"]=>
    string(2) "11"
    ["newTip"]=>
    string(1) "0"
  }
  [3]=>
  array(2) {
    ["id"]=>
    string(2) "12"
    ["newTip"]=>
    string(1) "0"
  }
}