Retrieve JSON Value error Undefined offset: 0

I have been having a hard time retrieving eth Value from a Json url for a while now, it keeps returning the error “Undefined offset: 0” as easy as it may be to anyone giving the answer, please consider that i am a learner and upcoming. My code below

$ethjs = "https://api.coingecko.com/api/v3/simple/token_price/ethereum?contract_addresses=0xdac17f958d2ee523a2206206994597c13d831ec7&vs_currencies=eth";
$ejson = file_get_contents($ethjs);
$ejson = json_decode($ejson, true);
$one_eth = $ejson[0]->eth;

Answer

The response from the url is something like

// https://api.coingecko.com/api/v3/simple/token_price/ethereum?contract_addresses=0xdac17f958d2ee523a2206206994597c13d831ec7&vs_currencies=eth
{
    "0xdac17f958d2ee523a2206206994597c13d831ec7": {
        "eth": 0.0003859
    }
}

Few things from above output

• There’s no [0] as you are trying to extract
• since this seems to be PHP which supports heterogeneous arrays, you need to access it via value of the contract_address parameter passed in url since that is the key in the result object.

Putting it altogether.

$ethjs = "https://api.coingecko.com/api/v3/simple/token_price/ethereum?contract_addresses=0xdac17f958d2ee523a2206206994597c13d831ec7&vs_currencies=eth";
$ejson = file_get_contents($ethjs);
$ejson = json_decode($ejson, true);
$one_eth = $ejson['0xdac17f958d2ee523a2206206994597c13d831ec7']['eth'];
echo $one_eth;