JSON manipulation in PHP? - php

Question

I need to edit some data in a JSON file, and I'm looking to do so in PHP. My JSON file looks like this:
[
{
"field1":"data1-1",
"field2":"data1-2"
},
{
"field1":"data2-1",
"field2":"data2-2"
}
]
What I've done so far is $data = json_decode(file_get_contents(foo.json)) but I have no idea how to navigate this array. If for example I want to find the data from the first field of the second object, what's the PHP syntax to do so? Also, are there other ways I should know about for parsing JSON data into a PHP friendly format?

Answer 1

This JSON contains 2 arrays with 2 objects each, you can access like this:
$arr = json_decode(file_get_contents(foo.json));
// first array
echo $arr[0]->field1;
echo $arr[0]->field2;
// second array
echo $arr[1]->field1;
echo $arr[1]->field2;
if you convert this to an array and avoid objects you can then access like this:
$arr = json_decode(file_get_contents(foo.json), true);
// first array
echo $arr[0]['field1'];
echo $arr[0]['field2'];
// second array
echo $arr[1]['field1'];
echo $arr[1]['field2'];

Answer 2

$data = json_decode(file_get_contents(foo.json));
foreach($data as $k => &$obj) {
$obj->field1 = 'new-data1-1';
$obj->field2 = 'new-data1-2';
}

Answer 3

Please use this code to navigate through your json format. This code is dynamic and can navigate for any number of objects you have in your result.
<?php
$json ='[
{
"field1":"data1-1",
"field2":"data1-2"
},
{
"field1":"data2-1",
"field2":"data2-2"
}
]';
if($encoded=json_decode($json,true))
{
echo 'encoded';
// loop through the json values
foreach($encoded as $key=>$value)
{
echo'<br>object index: '.$key.'<br>';
foreach($value as $bKey=>$bValue)
{
echo '<br> '.$bValue.' = '.$bValue;
}
}
// get a perticular item
echo '<br>object[0][field1]: '.$encoded[0]['field1'];
}
else
{
echo'error on syntax';
}
?>
Which will have following output
encoded
object index: 0
data1-1 = data1-1
data1-2 = data1-2
object index: 1
data2-1 = data2-1
data2-2 = data2-2
object[0][field1]: data1-1