<?php
//compact 将变量组合为数组
$key_1 = "val_1";
$key_2 = "val_2";
$data = array('$key_3'=>'val_3','$key_4'=>'val_4');
$arr_n =compact('key_1','key_2','data');
echo "compact:\n";
//extract根据键名导出变量
echo "extract:\n";
$arr_str = array('key_a'=>'val_a','key_b'=>'val_b','key_arr'=>array('1','2','3'));
extract($arr_str);
var_dump($key_a);
var_dump($key_b);
var_dump($key_arr);
// list(只作用于索引数组)用来取出数据。可只取出部分数据，如只取出前两个
echo "list:\n";
$arr_data =array('data_1','data_2','data_3','data_4');
list($v1,$v2)=$arr_data;
var_dump($v1);
var_dump($v2);
//list也可取变量放在数组指定位置中
list($data_res['0'],$data_res['5'])=$arr_data;
var_dump($data_res);
?>
