1. Convert it into a one-dimensional array and use min and max to find the minimum and maximum respectively

function getMaxAndMin($items){
    $newItems=[];
    $cutStr=',';//要分割的字符
    foreach($items as $item)
    {
    //保证是String并且包含','
      if(is_string($item) && strpos($item,$cutStr)!==false)
      {
        list($t1,$t2)=explode(',',$item)
        $newItems[]=$t1;
        $newItems[]=$t2;
       }else{
           $newItems[]=$item;
       }
    }
    return [min($newItems),max($newItems)];
}
$exampleArr=[
'0,129',
'130,249',
'250,459'
];
list($min,$max)=getMaxAndMin($exampleArr);

Add a downstairs plan, which is simpler
@jacoob_w

function getMaxAndMin($items,$operator=',')
{
    $data = explode($operator, join($operator,$data));
    return [min($data),max($data)];
}

<?php                                                                                                                                                                       
define('CLI_SCRIPT', true);                                                                                                                                                 
                                                                                                                                                                            
$example = array(                                                                                                                                                           
    '0, 129',                                                                                                                                                               
    '130, 249',                                                                                                                                                             
    '250, 459'                                                                                                                                                              
);                                                                                                                                                                          
$new_arr = [];                                                                                                                                                              
foreach ($example as $item) {                                                                                                                                               
    $new_items = explode(',', $item);                                                                                                                                       
    $new_arr = array_merge($new_arr, $new_items);                                                                                                                           
}                                                                                                                                                                           
var_dump($new_arr);                                                                                                                                                         
sort($new_arr, SORT_NUMERIC);    //排序                                                                                                                                     
$min = array_shift($new_arr);    //最小值                                                                                                                                   
$max = array_pop($new_arr);      //最大值                                                                                                                                           
var_dump($min);                                                                                                                                                             
var_dump($max);  

1. You can implement the algorithm manually, but the performance can be imagined
2. It is recommended to use PHP built-in functions: http://php.net/manual/zh/func...

$arr = array(
    '0,129',
    '130,249',
    '250,459',
);
$mix = intval($arr[0]);
$max = explode(',', end($arr))[1];

Use according to the actual situation
Because I saw that the questioner had other problems, I decided that his data structure is like this, and the size increases from top to bottom

I adopted the answer so quickly. I personally feel that the solution I adopted is not the best one.

$data = array(
    '0,129',
    '130,249',
    '380,22'
);

$dataArr = explode(',', join(',',$data));
echo "max:".max($dataArr)."<br/>";
echo "min:".min($dataArr);

$data = ['0,129','130,249','250,459'];
  $str=implode(',',$data);
  $arr=explode(',',$str);
  var_dump(max($arr));
  var_dump(min($arr));