PHP: How to get a value from a JSON file? - php

Question

I'm using PHP and json_decode to use a remote API and I'm having what seems to be a newbie problem for which I didn't even know what to search to find my answer.
So on my script I have a $code = 392 and a json file which simplified version is:
{
"result": {
"items": [
{
"name": "New York",
"code": 7294,
},
{
"name": "Miami",
"code": 392,
},
{
"name": "Los Angeles",
"code": 9182,
}
]
}
}
So, simply put, having the code 392 I want to know which name corresponds to that code. How ?
(The actual json result has thousands of "items", if that makes a difference)

Answer 1

At first you should decode your json data like:
// will decode json data as assoc array
$data = json_decode($json_data, true);
Then, you can get value in this array like:
$item01 = $data['result']['items'][0];
$name = $item01['name']; // New York
$code = $item01['code']; // 7294
Or
// will decode json data as object
$data = json_decode($json_data);
$item01 = $data->result->items[0];
$name = $item01->name; // New York
$code = $item01->code; // 7294

Answer 2

You can iterate through items in result of your JSON object, and check for equality with the desired code, and each item's code. Here's how you would implement it into a function.
function getNameFromCode($json, $code) {
foreach ($json['result']['items'] as $item)
if ($item['code'] == $code)
return $item['name'];
// return false if the code wasn't found.
return false;
}
// assume this is the JSON string of your example.
$json_string = "...";
// pass true as the second argument to get an associative array.
$json = json_decode($json_string, true);
// should return "Los Angeles".
$name = getNameFromCode($json, 9182);
Documenation on foreach().

Answer 3

foreach( json_decode($my_json_string) as $key => $item)
if ( $item['code'] === $code ) { $name = $item[name]; break; }

Answer 4

You can convert JSON to PHP object and loop through the items with foreach loop.
function getNameByCode($phpobj, $code){
if( isset($phpobj->result) ){
if( isset($phpobj->result->items)
&& is_array($phpobj->result->items) ){
foreach($phpobj->result->items as $item){
if( $item->code == $code ){
return $item->name;
}
}
}
}
return false;
}//end function
You can test with this ... NOTE: trailing commas are removed as suggest by rjdown in comment
$json = '{
"result": {
"items": [
{
"name": "New York",
"code": 7294
},
{
"name": "Miami",
"code": 392
},
{
"name": "Los Angeles",
"code": 9182
}
]
}
}';
$phpobj = json_decode($json);
$name = getNameByCode($phpobj, "7294");
echo $name;