Add values ​to array - php

Question

I'm trying to add random numbers with array_push to an array in the field 'notes' => [] but I think I'm not doing it right since I do not see the random numbers stored in the array.
I am doing it in the following way:
$person1= [
'name' => 'person1',
'note' => []
];
$person2= [
'name' => 'person2',
'note' => []
];
$person3= [
'name' => 'person3',
'note' => []
];
$data=[$person1, $person2, $person3];
$_SESSION['data'] = $data;
function insertNumRandom(){
$data = $_SESSION['data'];
foreach ( $data as $student ) {
array_push($student['note'], rand(0,10));
}
}
function showNotes(){
foreach ( $data as $student ) {
echo implode($student['note']);
}
}
showNotes(); // To show the notes but it shows nothing.

Answer 1

You should change insertNumRandom like as below
function insertNumRandom(){
$data = $_SESSION['data'];
foreach ( $data as &$student ) {
array_push($student['note'], rand(0,10));
}
$_SESSION['data'] = $data;
}
showNotes function
function showNotes(){
$data = $_SESSION['data'];
foreach ( $data as $student ) {
echo implode($student['note']);
}
}
and call insertNumRandom before showNotes.
insertNumRandom();
showNotes();

Answer 2

You're referencing the $data with the "as" keyword which creates a new object.
You should instead iterate through the object you already have.
function insertNumRandom(){
$index = 0;
for($index = 0; $index<sizeof($data['data']); $index++ ) {
array_push($data[$index]['note'], rand(0,10));
}
}

Answer 3

try this maybe, still not sure how you're calling the insertNumRandom() function
function showNotes($arr){
foreach ( $arr as $student ) {
var_dump(implode($student['note']));
}
}
insertNumRandom();
showNotes($data);

Answer 4

you have a number of issues in your example.
First of all, the way you are using the $_SESSION object to pass some values to the function is not necessary, and not clean. You can either use global $data inside of the functions and they will suddenly have access to the $data variable from the parent scope. But even that is not very clean. I would suggest that you pass the data object by reference to the functions. That will make your function more portable and testable.
Your example is accessing the $student variable by value. All you need to do is to access it by reference by using the ampersand (&) in the foreach() like this foreach ( $data as &$student ) { ... }
I have noticed that you have never made a single call to insertNumRandom()
To have a better idea about what's in the arrays, I would suggest that you use a field separator for the implode() function and that you print a new line after imploding the array. I bet you will like the result.
Finally, just a word of advice ... array_push() lets you push one or more items in an array. But I personally use it only when I need to push multiple items in an array. For push just item new items, I use the short-hand $myArray[] = "new item";
So in practice, here is what your example will become ...
<?php
// Since you are not reusing $person1, $person2 and $person3 beyond the initialization
// phase, then let's keep things cleaner.
$data[] = [
'name' => 'person1',
'note' => []
];
$data[] = [
'name' => 'person2',
'note' => []
];
$data[] = [
'name' => 'person3',
'note' => []
];
/**
* In this function signature, the & means that the argument is passed by reference.
* That make it possible for the function to change the value of the argument.
*/
function insertNumRandom(&$theData) {
// The foreach() also needs to use $student by reference so that we can modify it
// by adding the random number to it.
foreach($theData as &$student) {
$student['note'][] = rand(0,10);
}
}
/**
* No need to pass $theData by reference because the function will not change its value.
*/
function showNotes($theData) {
// Here, the foreach() is using student by value because we do not need to change it's value.
foreach($theData as $student) {
echo implode($student['note'], ', ') . "\n";
}
}
// Inserting some random notes 3 times.
insertNumRandom($data);
insertNumRandom($data);
insertNumRandom($data);
showNotes($data); // To show the notes but it shows nothing.
?>