How do I get specific things out of an array? Eg., make them into their own variable?

[peterhuynh]

Here is the code:

 

$ch = curl_init('some_api_information');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
$result = curl_exec($ch);

 

It prints this out:

 

{ "high":"8650.00", "last":"8500.00", "timestamp":"1410341807", "bid":"8310.00", "vwap":"8414.15", "volume":"107.05882350", "low":"8480.00", "ask":"8500.00" }

 

I want to make, e.g., "low", into a variable.

 

Thanks a bunch. I'm new to php.

[NotionCommotion]

Looks like JSON to me.  Look into http://php.net/manual/en/function.json-decode.php

[peterhuynh]

Looks like JSON to me.  Look into http://php.net/manual/en/function.json-decode.php

 

Thank you!

 

I'm really new at this, could you give me another pointer?

[NotionCommotion]

Execute the following script.

<?php
  $json='{ "high":"8650.00", "last":"8500.00", "timestamp":"1410341807", "bid":"8310.00", "vwap":"8414.15", "volume":"107.05882350", "low":"8480.00", "ask":"8500.00" }';
  $array=json_decode($json);
  echo('<pre>'.print_r($array,1).'</pre>');
?>

[NotionCommotion]

Did you look at the link I sent you?

[peterhuynh]

Yes I did. Thank you for the link. I studied it as much as I could. But I'd like to emphasize I'm a supernoob.

 

Some context:

the api grabs ticker infornation. So the results that it prints out isn't actually what I posted above; it will print out different results every time.

 

In the script you provided, you used the exact print out. So I don't think it will work out that way. Does that make sense?

 

Thanks,

P

[NotionCommotion]

I was just giving an example on how json_decode() works.  Try the following.  The print_r() is just to show you what is happening.  Given some json, you use json_encode() to turn it into an array, and then you access the various array elements as you desire.

<?php
$ch = curl_init('some_api_information');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
$result = curl_exec($ch);
$array=json_decode($result);
echo('<pre>'.print_r($array,1).'</pre>');
$low=$array['low'];
echo($low);
?>

[CroNiX]

 

Given some json, you use json_encode() to turn it into an array, and then you access the various array elements as you desire.

 

I'm sure you just mispoke, but to be clear, you use json_decode() to turn it from a json string into a php array, not json_encode(), which is the opposite.

[NotionCommotion]

I'm sure you just mispoke, but to be clear, you use json_decode() to turn it from a json string into a php array, not json_encode(), which is the opposite.

Go by my script, not my narrative 

[peterhuynh]

 

I was just giving an example on how json_decode() works.  Try the following.  The print_r() is just to show you what is happening.  Given some json, you use json_encode() to turn it into an array, and then you access the various array elements as you desire.

<?php
$ch = curl_init('some_api_information');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
$result = curl_exec($ch);
$array=json_decode($result);
echo('<pre>'.print_r($array,1).'</pre>');
$low=$array['low'];
echo($low);
?>

Hi, Thanks for your help.

 

I've been trying to figure out this stuff as I go, as to not keep asking people whenever I have a problem. But I couldn't figure it out.

 

When I try to echo $low, I get this message: "Fatal error: Cannot use object of type stdClass as array".

 

When I echo ('<pre>'.print_r($array,1).'</pre>'), I get this:

stdClass Object(    [high] => 285.50    [last] => 277.00    [timestamp] => 1423414632    [bid] => 275.00    [vwap] => 280.08    [volume] => 199.25328242    [low] => 274.69    [ask] => 277.00)

[Barand]

By default, json_decode returns an object as you have done

$obj=json_decode($result);

So to access "low" you would use

$low = $obj->low;

If you want an array then you need the second argument of json_decode to be true EG

$array = json_decode($result, 1);

Then you can access low with

$low = $array['low'];

[peterhuynh]

 

By default, json_decode returns an object as you have done

$obj=json_decode($result);

So to access "low" you would use

$low = $obj->low;

If you want an array then you need the second argument of json_decode to be true EG

$array = json_decode($result, 1);

Then you can access low with

$low = $array['low'];

 

 

 

I was just giving an example on how json_decode() works.  Try the following.  The print_r() is just to show you what is happening.  Given some json, you use json_encode() to turn it into an array, and then you access the various array elements as you desire.

<?php
$ch = curl_init('some_api_information');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
$result = curl_exec($ch);
$array=json_decode($result);
echo('<pre>'.print_r($array,1).'</pre>');
$low=$array['low'];
echo($low);
?>

 

Thanks, guys! I actually made something work in programming.

 

Is there a tipping service on this forums? If you guys have a bitcoin wallet, I'd like to send you something.

 

Another question: How do get specific things when the array is a set of sets?

 

For instance, my original problem was that I needed to get something out and turn it into a variable. The set looked like this: {"a":"1", "b":"2", "c":"3"}.

 

Now I need to get things that are members of a subset of the original set. E.g., {"bids": [[0.010010000, 150.000000000], [0.121000000, 82.000000000]], "asks": [[1700.000000000, 1.000000000],[282.365000000, 1.000000000]]}. Specifically, how do I get the lowest "asks"?

[Barand]

is this the result you are looking for?

$results = '{"bids": [[0.010010000, 150.000000000], [0.121000000, 82.000000000]], "asks": [[1700.000000000, 1.000000000],[282.365000000, 1.000000000]]}';
$arr = json_decode($results, 1);
$asks = $arr['asks'];
sort($asks);
echo $asks[0][0];  //--> 282.365

[peterhuynh]

 

is this the result you are looking for?

$results = '{"bids": [[0.010010000, 150.000000000], [0.121000000, 82.000000000]], "asks": [[1700.000000000, 1.000000000],[282.365000000, 1.000000000]]}';
$arr = json_decode($results, 1);
$asks = $arr['asks'];
sort($asks);
echo $asks[0][0];  //--> 282.365

 

Sorry, i was wrong about the contents of $results.

 

$results =

Response (example):

{“status”: ok | error,

“apirate”: apirate,

“message”: “” | error message,

“orderbook” :

{“bids”:

List [

List [

Pos 0 = Price

Pos 1 = Amount of currency per order

]

]

“asks”:

List [

List [

Pos 0 = Price

Pos 1 = Amount of currency per order

]

]

}

}

 

[NotionCommotion]

You really got a response like that?  It doesn't appear to be valid JSON.

 

On a side note, I am going to stress that you use the following code often when starting off.  You could also use var_dump($array) which actually gives you more information, but the below is easier to read when you are new.

echo('<pre>'.print_r($myvariable,1).'</pre>');

For instance, maybe one of your variables includes something crazy like the below.  Where do you start?  Well, print_r first tells you that the top part is an object.  That means that you access properties using ->someobjectpropertier (as apposed to ['somearrayelement'] for an array).  someobjectpropertier and somearrayelement are just names I picked, and don't mean anything special.  As you go down, print_r tells you if it is an object, an array, or if neither, a string.

 

So, if I need something_I_need, I could use $myvariable->myarray['myobject']->something_I_need.  Make sure you understand this perfectly as you will be doing this often.

stdClass Object(    [high] => 8650.00    [last] => 8500.00    [timestamp] => 1410341807    [bid] => 8310.00    [vwap] => 8414.15    [volume] => 107.05882350    [low] => 8480.00    [ask] => 8500.00    [myarray] => Array        (            [high] => 8650.00            [last] => 8500.00            [timestamp] => 1410341807            [bid] => 8310.00            [vwap] => 8414.15            [volume] => 107.05882350            [low] => 8480.00            [ask] => 8500.00            [myobject] => stdClass Object                (                    [high] => 8650.00                    [last] => 8500.00                    [timestamp] => 1410341807                    [bid] => 8310.00                    [vwap] => 8414.15                    [volume] => 107.05882350                    [low] => 8480.00                    [ask] => 8500.00                    [something_I_need] => The Prize!                )        ))