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Help with Looping through an object - enelson - 11-10-2018

Hi all,
i have a JSON that looks similar to one shown below:
Code:
products: [
    {
        id: "D-MFIN-2-150MB",
        pur_currency: "NN",
        topup_amount: 200,
        price: 200,
        data_amount: "150"
    },
    {
        id: "D-MFIN-2-1",
        pur_currency: "NN",
        topup_amount: 1000,
        price: 1000,
        data_amount: "1000"
    },
    {
        id: "D-MFIN-2-1.5",
        pur_currency: "NN",
        topup_amount: 1200,
        price: 1200,
        data_amount: "1500"
    },
    {
        id: "D-MFIN-2-2.5",
        pur_currency: "NN",
        topup_amount: 2000,
        price: 2000,
        data_amount: "2500"
    },
    {
        id: "D-MFIN-2-4",
        pur_currency: "NN",
        topup_amount: 3000,
        price: 3000,
        data_amount: "4000"
    },
    {
        id: "D-MFIN-2-11.5",
        pur_currency: "NN",
        topup_amount: 8000,
        price: 8000,
        data_amount: "11500"
    },
    {
        id: "D-MFIN-2-15",
        pur_currency: "NN",
        topup_amount: 10000,
        price: 10000,
        data_amount: "15000"
    },
    {
        id: "D-MFIN-2-27.5",
        pur_currency: "NN",
        topup_amount: 18000,
        price: 18000,
        data_amount: "27500"
    },
    {
        id: "D-MFIN-2-30",
        pur_currency: "NN",
        topup_amount: 27500,
        price: 27500,
        data_amount: "30000"
    },
    {
        id: "D-MFIN-2-60",
        pur_currency: "NN",
        topup_amount: 55000,
        price: 55000,
        data_amount: "60000"
    },
    {
        id: "D-MFIN-2-100",
        pur_currency: "NN",
        topup_amount: 84992,
        price: 84992,
        data_amount: "100000"
    },
    {
        id: "D-MFIN-2-120",
        pur_currency: "NN",
        topup_amount: 110000,
        price: 110000,
        data_amount: "120000"
    },
    {
        id: "D-MFIN-2-500MB",
        pur_currency: "NN",
        topup_amount: 500,
        price: 500,
        data_amount: "500"
    },
    {
        id: "D-MFIN-2-5.5",
        pur_currency: "NN",
        topup_amount: 4000,
        price: 4000,
        data_amount: "5500"
    },
    {
        id: "D-MFIN-2-40MB",
        pur_currency: "NN",
        topup_amount: 100,
        price: 100,
        data_amount: "40"
    }
]

I want to loop through it and display in a select tag. I've failed to do that so far.
To test I converted the JSON to PHP objects using $list = json_decode), then:
PHP Code:
for ($i=0$i count($list); $i++) { 
echo 
"Item no. {$i} is {$list->$i->$id} <br>";

That gives an error:
Code:
A PHP Error was encountered
Severity: Notice

Message: Trying to get property of non-object
Next, id did
PHP Code:
for ($i=0$i count($list); $i++) { 
echo 
"Item no. {$i} is {$list[$i]['id']} <br>";

This was worse:
Code:
An uncaught Exception was encountered
Type: Error

Message: Cannot use object of type stdClass as array
I was able ot do this:
PHP Code:
for ($i=0$i count($list); $i++) { 
echo 
"Item no. {$i} <br>";

to just count the object.

My question, how can I get id, pur_currency, etc... from the $list variable.
Your answer is appreciated.


RE: Help with Looping through an object - jreklund - 11-10-2018

It should be used like this as your JSON are stored as objects inside an array.
{$list[$i]->id}

$list = array with multiple arrays.
$list[$i] = returns an object.
$list[$i]->id = returns the ID inside that object.

Personally I would just use a foreach loop instead.
PHP Code:
foreach($list as $row) {
    echo 
$row->id;


In case you don't need the position in that array.


RE: Help with Looping through an object - paulkd - 11-11-2018

Hi,

Your json format is incorrect. json keys should be in double quotes.

It should look like this:

Code:
{
"products": [
   {
       "id": "D-MFIN-2-150MB",
       "pur_currency": "NN",
       "topup_amount": 200,
       "price": 200,
       "data_amount": "150"
   },
   {
       "id": "D-MFIN-2-1",
       "pur_currency": "NN",
       "topup_amount": 1000,
       "price": 1000,
       "data_amount": "1000"
   }
]
}

Decode as normal
Code:
$list = json_decode($json);

Your for loop would then iterate like this:

Code:
for ($i=0; $i < count($list->products); $i++) {
echo "Item no. {$i} is {$list->products[$i]->id} <br>";
}

or, as jreklund points out, foreach is the best way to iterate:

Code:
foreach ($list->products as $key => $row) {
echo "Item no. {$key} is {$row->id} <br>";
}



RE: Help with Looping through an object - InsiteFX - 11-11-2018

It is faster to get the count first before running a for loop.
Otherwise you are calling the count method on each loop irritation.

PHP Code:
$count count($list->products);
for (
$i=0$i $count$i++) { 
echo 
"Item no. {$i} is {$list->products[$i]->id} <br>";




RE: Help with Looping through an object - enelson - 11-11-2018

(11-11-2018, 12:52 AM)paulkd Wrote: Hi,

Your json format is incorrect. json keys should be in double quotes.
...

I removed some part of the JSON before posting here - that inclusive.

Thanks all for your replies, they were helpful.


RE: Help with Looping through an object - enelson - 11-11-2018

Another issue I have is that I want to sort $list in ascending order by "data_amount".
asort(), ksort() etc are returning bool(true) instead of the $list objects - and they should be.

Any ideas as to how I can sort the $object?


RE: Help with Looping through an object - paulkd - 11-11-2018

Do you have control of what is producing the json?

If so, maybe you can use that process to sort (e.g. SQL query)


RE: Help with Looping through an object - enelson - 11-11-2018

(11-11-2018, 10:43 AM)paulkd Wrote: Do you have control of what is producing the json?
No, I'am receiving it via API call


RE: Help with Looping through an object - InsiteFX - 11-11-2018

You could decode the json into an associated array sort it and then encode it back to json
and then create your list.


RE: Help with Looping through an object - paulkd - 11-12-2018

Hi,

I got this answer from https://stackoverflow.com/questions/4282413/sort-array-of-objects-by-object-fields

Code:
$list = json_decode($json);

function cmp($a, $b) {
   return strcmp($a->data_amount, $b->data_amount);
}

usort($list->products, "cmp");