PHP循环体内给数组赋值

<?php
$list = [1, 2, 3];
foreach ($list as $value) {
    if($value != 2){
        $data[0] = $value ;
    }
    var_dump($data) ; 
}
/**
array(1) {
  [0]=>int(1)
}
array(1) {
  [0]=>int(1)
}
array(1) {
  [0]=>int(3)
}
*/

<?php
$list = [1, 2, 3];
foreach ($list as $value) {
    // 先初始化数组
    $data = [] ; 
    if($value != 2){
        $data[0] = $value ;
    }
    var_dump($data) ; 
}
/**
array(1) {
  [0]=>int(1)
}
array(0) {
}
array(1) {
  [0]=>int(3)
}
[Finished in 0.1s]
*/