数组

<?php
  // 数组的两种形式
  // 1. $arr = (1,2,3)  默认key是从0开始的整数
  // 2.$arr = ("a"=>"1","b"=>"2","c"=>"3");

  $arr = array(1, 2, 3);
  echo $arr[0];
  echo '<br>';
  print_r($arr);
  $arr1 = array('name' => 'zs', 'age' => '18');
  echo '<br>';
  echo $arr1['name'];
  echo '<br>';
  print_r($arr1);
  echo '<br>';
  var_dump($arr1);
  echo '<br>';

  // 二维数组
  $arr2 = array();
  $arr2[0] = array(1, 2, 3);
  $arr2[1] = array(4, 5, 6);
  $arr2[2] = array(7, 8, 9);
  print_r($arr2);
  // Array (
  //   [0] => Array ( [0] => 1 [1] => 2 [2] => 3 )
  //   [1] => Array ( [0] => 4 [1] => 5 [2] => 6 )
  //   [2] => Array ( [0] => 7 [1] => 8 [2] => 9 )
  //   )
  echo '<br>';
  $arr3 = array();
  $arr3['apple'] = array('color' => 'red', 'shape' => 'round');
  $arr3['orange'] = array('color' => 'orange', 'shape' => 'round');
  $arr3['banana'] = array('color' => 'yellow', 'shape' => 'long');
  print_r($arr3);
  echo '<br>';
  echo $arr3['apple']['color'];

  // Array (
  //   [apple] => Array ( [color] => red [shape] => round )
  //   [orange] => Array ( [color] => orange [shape] => round )
  //   [banana] => Array ( [color] => yellow [shape] => long )
  //   )
  ?>