Update value inside array update_post_meta

Question

I am trying to change default values inside array in custom field.

But I am getting error "PHP Fatal error: Uncaught Error: Cannot use string offset as an array" when I try to change the value using following code.

Strangely I use this code in default page template and it works there when I statiscally provide the post id..

but gives error for following code

add_action('pending_to_publish', 'oj_publish_campaign',10 ,1);

function oj_publish_campaign($post) {
    global $wpdb;
    $t = get_post_meta( $post->ID, '_give_donation_levels', true ); 
    $t[0]["_give_amount"] = 25.00;    // getting error here 
    $t[1]["_give_amount"] = 65.00;
    $t[2]["_give_amount"] = 100.00;
    $t[3]["_give_amount"] = 250.00;
    $t[4]["_give_amount"] = 650.00;    

    update_post_meta( $post->ID, '_give_donation_levels', $t );
}

this is how the initial array for the custom field looks like

And the strange thing is that it works inside a page-template i.e

if I create a page "Test" and assign it the following template and just load the page , it updates the fields as required

/*
Template Name: Test
*/
get_header();
while ( have_posts() ) : the_post();

$p = 2234;

$t = give_get_meta( $p, '_give_donation_levels', true );
echo "<pre>"; var_dump($t);echo "</pre>";

$t[0]["_give_amount"] = 25.00;
$t[1]["_give_amount"] = 65.00;
$t[2]["_give_amount"] = 100.00;
$t[3]["_give_amount"] = 250.00;
$t[4]["_give_amount"] = 650.00;

update_post_meta( $p, '_give_donation_levels', $t );        
endwhile; // End of the loop.
get_footer();

Can anyone please help me with this

thanks in advance

Answer 1

The structure of the array you've provided suggests that you're trying to access an incorrect level of the array. Try to replace:

$t[0]["_give_amount"] = 25.00;
$t[1]["_give_amount"] = 65.00;
$t[2]["_give_amount"] = 100.00;
$t[3]["_give_amount"] = 250.00;
$t[4]["_give_amount"] = 650.00;

with:

$t[0][0]["_give_amount"] = 25.00;
$t[0][1]["_give_amount"] = 65.00;
$t[0][2]["_give_amount"] = 100.00;
$t[0][3]["_give_amount"] = 250.00;
$t[0][4]["_give_amount"] = 650.00;