PHP 获取数组中某个值等5中的数组(指定的一列实例)(多维数组)

例子：

array(4) {
  ["code"] => int(200)
  ["msg"] => string(6) "成功"
  ["count"] => int(12)
  ["data"] => array(5) {
    ["data_0"] => array(12) {
      [1] => string(6) "首页"
      [3] => string(12) "直播课程"
      [4] => string(12) "录播课程"
      [5] => string(12) "在线题库"
      [6] => string(6) "团队"
      [7] => string(6) "资讯"
      [8] => string(6) "商城"
      [9] => string(6) "论坛"
      [11] => string(12) "新手指南"
      [12] => string(12) "帮助中心"
      [18] => string(12) "在线招聘"
      [14] => string(12) "关于我们"
    }
    ["data_1"] => array(10) {
      [3] => array(2) {
        [26] => string(6) "教师"
        [25] => string(6) "自考"
      }
      [4] => array(2) {
        [34] => string(7) "自考1"
        [33] => string(7) "教师1"
      }
      [5] => array(3) {
        [41] => string(6) "教师"
        [40] => string(6) "人力"
        [39] => string(6) "自考"
      }
      [6] => array(3) {
        [53] => string(6) "人力"
        [52] => string(6) "教师"
        [51] => string(6) "会计"
      }
      [7] => array(3) {
        [59] => string(6) "公告"
        [58] => string(12) "行业新闻"
        [57] => string(12) "公司新闻"
      }
      [8] => array(2) {
        [61] => string(6) "自考"
        [60] => string(9) "计算机"
      }
      [11] => array(6) {
        [70] => string(12) "交流社区"
        [69] => string(12) "疑难问答"
        [68] => string(9) "VIP购买"
        [67] => string(12) "意见反馈"
        [66] => string(15) "请修改标题"
        [65] => string(15) "请修改标题"
      }
      [12] => array(5) {
        [75] => string(12) "如何支付"
        [74] => string(12) "注册账号"
        [73] => string(12) "新手入门"
        [72] => string(12) "发布须知"
        [71] => string(15) "请修改标题"
      }
      [18] => array(3) {
        [78] => string(15) "技术部招聘"
        [77] => string(15) "市场部招聘"
        [76] => string(15) "文职类招聘"
      }
      [14] => array(2) {
        [80] => string(12) "关于我们"
        [79] => string(12) "联系方式"
      }
    }
    ["data_2"] => array(12) {
      [26] => array(2) {
        [28] => string(6) "中学"
        [27] => string(6) "小学"
      }
      [25] => array(2) {
        [30] => string(6) "专科"
        [29] => string(6) "本科"
      }
      [34] => array(2) {
        [36] => string(6) "博士"
        [35] => string(9) "研究生"
      }
      [33] => array(2) {
        [38] => string(7) "小学2"
        [37] => string(7) "中学2"
      }
      [41] => array(3) {
        [44] => string(6) "小学"
        [43] => string(6) "中学"
        [42] => string(6) "高中"
      }
      [40] => array(2) {
        [46] => string(7) "中学1"
        [45] => string(7) "小学1"
      }
      [39] => array(2) {
        [48] => string(12) "行管本科"
        [47] => string(12) "行管专科"
      }
      [53] => array(1) {
        [54] => string(6) "大专"
      }
      [52] => array(1) {
        [55] => string(6) "大专"
      }
      [51] => array(1) {
        [56] => string(6) "大专"
      }
      [61] => array(1) {
        [62] => string(21) "专科升本科密级"
      }
      [60] => array(2) {
        [64] => string(8) "JS教程"
        [63] => string(9) "PHP教程"
      }
    }
    ["data_3"] => array(3) {
      [28] => array(1) {
        [32] => string(15) "请修改标题"
      }
      [30] => array(1) {
        [31] => string(15) "请修改标题"
      }
      [44] => array(2) {
        [50] => string(21) "教育知识与能力"
        [49] => string(12) "综合素质"
      }
    }
    ["data_4"] => NULL
  }
}

比如要取得data_1数组值3的数组

$indexmenudata['data']['data_1']['3'];

结果：

array(2) {
  [26] => string(6) "教师"
  [25] => string(6) "自考"
}

 

对于一个多维数组(以二维数组为例)，经常需要获取到其中的一列，比如有几条用户数据，是一个二维数组，现在需要获取到这几个用户的名字，可以有多种方法实现：

$arr = array(
  array(
    'id'=>'101',
    'name'=>'qu',
    'age'=>28
  ),
  array(
    'id'=>'102',
    'name'=>'you',
    'age'=>24
  ),
  array(
    'id'=>'103',
    'name'=>'zheng',
    'age'=>22
  ),
  array(
    'id'=>'104',
    'name'=>'zhu',
    'age'=>23
  )
);

方法一：使用PHP内置函数array_column()实现

array array_column ( array $input , mixed $column_key [, mixed $index_key ] )

执行语句:

$result = array_column($arr,'name')； 
print_r($result);

结果如下:

Array 
( 
 [0] => qu 
 [1] => you 
 [2] => zheng 
 [3] => zhu 
)

如果指定了可选参数index_key，那么input数组中的这一列的值将作为返回数组中对应值的键。

$result = array_column($arr,'name','id'); 
print_r($result);

结果如下:

Array 
( 
 [101] => qu 
 [102] => you 
 [103] => zheng 
 [104] => zhu 
)

方法二：使用PHP内置函数array_map()实现

array array_map ( callable $callback , array $arr1 [, array $... ] )

array_map() 返回一个数组，该数组包含了 arr1 中的所有单元经过 callback 作用过之后的单元。其中第一个参数是一个回调函数，返回值是一个数组，该数组的每个元素都数组（arr1）里面的每个元素经过回调函数（callback）处理了的。

先声明一个处理函数:

function get_val($arr){ 
 return $arr['name']; 
}

然后作用于array_map()函数:

$result = array_map('get_val',$arr); 
print_r($result);

执行结果如下:

Array 
( 
 [0] => qu 
 [1] => you 
 [2] => zheng 
 [3] => zhu 
)

此处array_map()的第一个参数是一个回调函数，而且是事先定义好的有名函数，这里我们也可以像js一样使用匿名函数：

$result = array_map(function($v){ 
 return $v['name']; 
},$arr);

其执行结果是一样的。