Entity JSON encode and manually decode

That's not in json format, that's encoded with serialize(). You need to use unserialize() to decode it back to an array.

Got it! Thanks.
The unserialize() worked perfectly.
But I am having following code in my Entity...

PHP Code:

protected $casts = [
    'courses'        => 'array',
    'courses_object' => 'json',
    'courses_array'  => 'json-array',
]; 


The CodeIgniter is using word 'json' here?