Parsing JSON keys and values in PHP - php

Question

These are the values in JSON
"_id": "5db81ae803f7410018f7c081",
"hotness": 72793.81406699134,
"activityHotness": 0.10295588022415446,
"primaryCategory": "Exchanges",
"words": 443,
"similarArticles": [],
"coins": [
{
"_id": "59cb59e81c073f09e76f614b",
"name": "Bitcoin",
"slug": "bitcoin",
"tradingSymbol": "btc"
},
{
"_id": "59d21e9b83a0523906a45dc5",
"name": "EOS",
"slug": "eos",
"tradingSymbol": "eos"
},
{
"_id": "59d21e9b83a0523906a45dbe",
"name": "Tether",
"slug": "tether",
"tradingSymbol": "usdt"
}
],
"description": "The world’s 5th largest crypto exchange OKEx is planning to launch Tether futures trading, offering a linear futures contract with leverage of up to 100x.\nThe world’s 5th largest crypto exchange OKEx is planning to launch Tether ( USDT ) futures trading, offering a linear futures contract with…",
"publishedAt": "2019-10-29T10:16:00.000Z",
"title": "OKEx to Launch USDT Futures Trading With Up to 100x Leverage",
"url": "https://cryptocontrol.io/r/api/article/5db81ae803f7410018f7c081?ref=5d9f090e03f7410018f41938",
"source": {
"_id": "59d70be3ef8bf95cc2aa2b4f",
"name": "CoinTelegraph",
"url": "https://cointelegraph.com/",
"favicon": "https://assets.cryptocontrol.io/favicons/59d70be3ef8bf95cc2aa2b4f.png"
},
"sourceDomain": "cointelegraph.com",
"originalImageUrl": "https://images.cointelegraph.com/images/740_IGh0dHBzOi8vczMuY29pbnRlbGVncmFwaC5jb20vc3RvcmFnZS91cGxvYWRzL3ZpZXcvMWY5YTllNWViMGI1NTNhMWJkNWVlYjBhZWNkOTAxYzkuanBn.jpg"
},
I want to truncate the values from Id to coins and display the values starting from description
I am trying to get keys and values from the JSON file in Blockchain array. But I want to truncate some of them. Not getting idea how to do.
I have tried using foreach loop
<?php
$getJsonData = file_get_contents("sample.json");
$jsonArray = json_decode($getJsonData);
$mainName = "blockchain";
$i = 1;
foreach($jsonArray->$mainName as $row){
echo "<br>----------record $i start <br><br>";
foreach($row as $key => $val){
if(is_object($val)){
foreach($val as $ky => $v1){
echo $key.' => '.$ky.': '.$v1;
echo '<br>';
}
}else{
echo $key.': '.$val;
echo '<br>';
}
}
echo "<br>----- record $i end <br><br>";
$i++;
}
?>

Answer 1

Since you call json_decode() without the optional second argument, the JSON objects are decoded as PHP objects, not associative arrays. So you can't use foreach() to loop over the object properties.
Use json_decode($getJsonData, true) and then all the objects will become associative arrays.
Then you can use array_keys() to get all the keys, and remove all the keys between _id and coins.
$keys = array_keys($jsonArray[$mainName][0]);
$id_index = array_search('_id', $keys);
$coins_index = array_search('coins', $keys);
array_splice($keys, $id_index, $coins_index - $id_index + 1); // remove keys from _id to coins
foreach ($jsonArray[$mainName] as $row) {
foreach ($keys as $key) {
$val = $row[$key];
if (is_array($val)) {
foreach ($val as $k => $v) {
echo "$key => $k: $v<br>";
}
} else {
echo "$key: $val<br>";
}
}
}