Changing the in-place value of array with PHP - php

Question

I want to modify a value inside JSON. Let's say I have this example JSON and I want to have the php change the phone number:
$data = '{
"firstName": "John",
"lastName": "Smith",
"age": 27,
"phoneNumbers": [
{
"type": "home",
"number": "212 555-1234"
}
]
}'
It sounds like I have to convert to an array using json decode:
$data = json_decode($data,true);
Which gives me this:
array (
'firstName' => 'John',
'lastName' => 'Smith',
'age' => 27,
'phoneNumbers' =>
array (
0 =>
array (
'type' => 'home',
'number' => '212 555-1234',
),
),
)
How do I then insert my own variable value into the array please? From my googling it looks like I might be on the right path with something along these lines:
$number = '50';
$data[$key]['age'] = $number;
What it does though, is just add it onto the end of the array, instead of correcting the value in place of the array file.

Answer 1

Firstly, you need to convert your json to PHP array usign json_decode function. check below code for updating/inserting keys:
$data['age'] = $number; // to update age
$data['newkey'] = 'newvalue'; //it will add key as sibling of firstname, last name and further
$data['phoneNumbers'][0]['number'] = '222 5555 4444'; //it will change value from 212 555-1234 to 222 5555 4444.
You just need to consider array format. If key exists then you can update value else it will be new key in array. Hope it helps you.