<?php
header("content-type:text/html;charset=utf-8");   
$thai_data = '[{
		"id": "1",
		"zip": "10200",
		"province": "กรุงเทพมหานคร",
		"district": "พระนคร",
		"lat": 13.7560243,
		"lng": 100.4986793
	},
	{
		"id": "2",
		"zip": "10300",
		"province": "กรุงเทพมหานคร",
		"district": "ดุสิต",
		"lat": 13.7726943,
		"lng": 100.5099262
	}]';
$data = iconv("tis-620","utf-8",$thai_data);
$data = json_decode($data);
echo "<pre>";
var_dump($data); 
echo "</pre>";
foreach($data as $key => $val) { echo $key . " = " . $data[$key]->{'zip'}. "<br/>";  }
?>