- substr: documentation ( source)
- preg_replace_callback: documentation ( source)
- print_r: documentation ( source)
- explode: documentation ( source)
- preg_replace: documentation ( source)
<?php
$str = "[[1500000000,2823.43,2848,2827.86,2847.68,526.4426911499979]]";
$str2 = substr($str,1,-1);
$arr = [];
preg_replace_callback('/\[(.*?)\]/', function($m) use (&$arr){
$arr[] = explode(',',preg_replace('/([\w]+)/', "$1", $m[1]));
}, $str2);
print_r($arr);