JSON parse in PHP

JSON parse in PHP

Suppose you want to parse listed below JSON data in PHP and you only needed to print objectId values. you can see here 3 records under merchants value "RPEZF3MRM39Z0"

-----------------------------------------------------------------------
{
"appId": "0QA16KMMVJAQR",
"merchants": {
"RPEZF3MRM39Z0": [{
"objectId": "O:S1MXC6FCY6GDW",
"type": "UPDATE",
"ts": 1453110818494
}, {
"objectId": "O:S1MXC6FCY6GDW",
"type": "UPDATE",
"ts": 1453110818913
}, {
"objectId": "P:SYD46NHH64EQG",
"type": "CREATE",
"ts": 1453110818913
}]
}
}
------------------------------------------------------------------------

php code:

suppose $st is hlding the above json data.

$json_a=json_decode($st,true);
foreach ( $json_a['merchants']['RPEZF3MRM39Z0'] as $objectId )
{
    echo $objectId['objectId']."</br>";
}