How to get the 0th index key values in array object - php

Question

I have one array object in that object galleryImages i having like json string , in this galleryImages i want display onely the first image value , how can get the only first image value?
My array check below
$data=Array
(
[dbResultgallery] => Array
(
[0] => stdClass Object
(
[gallery_id] => 1
[className] => 1
[sectionName] => 1
[title] => Title 1
[description] => gfhfg
[galleryImages] => ["1.jpeg","2.jpg"]
[reg_on] => 2017-04-03 12:21:59
[created_by] => soupranjali#gmail.com
[school_id] => 2
[status] => 0
)
[1] => stdClass Object
(
[gallery_id] => 2
[className] => 1
[sectionName] => 1
[title] => Title 2
[description] => sdfdsfsdfsdfsdf
[galleryImages] => ["3.jpeg","4.jpg","5.jpg"]
[reg_on] => 2017-04-03 12:23:37
[created_by] => soupranjali#gmail.com
[school_id] => 2
[status] => 0
)
)
)
now i am using json_decode ,see below my code
foreach ($dbResultgallery as $gal) :
$role = json_decode($gal->galleryImages,true);
endforeach;
Now i am getting array format like
Array
(
[0] => 1.jpeg
[1] => 2.jpg
)
Array
(
[0] => 3.jpeg
[1] => 4.jpg
[2] => 5.jpg
)
Expected results
I need only the first images value like 1.jpeg and 3.jpeg, each array i need only the 0 th key values
Updated code
var_dump(json_decode($gal->galleryImages,true))
array(2) {
[0]=>
string(37) "6be1954c4bec91fe26fb7447fc551782.jpeg"
[1]=>
string(36) "153651d989591e76444c92cf037d5ac4.jpg"
}
array(3) {
[0]=>
string(37) "f356ceafa408e61cd1c62cfc39752b32.jpeg"
[1]=>
string(36) "a4fd29005696d92e0fc4cd3931454609.jpg"
[2]=>
string(36) "8eaaecdac1ff219192806acba7978a1b.jpg"
}

Answer 1

Change to this:
$role = json_decode($gal->galleryImages,true)[0];

Answer 2

foreach ($dbResultgallery as $gal) :
if(strpos(json_decode($gal->galleryImages,true) ,"jpeg")!== false){
echo 'found'; // do your stuff here
$role = json_decode($gal->galleryImages[0],true);
}
endforeach