let s = {'year' : 2023, 
             'animal' : ['dog', 'cat', 'cow', 'fox', 'rat']
            }

    " Encode text string to json object
    let json = json_encode(s)
    echo json
    " ⟹  {"year": 2023, "animal": ["dog", "cat", "cow", "fox", "rat"]}

    " Decode json object to text string
    let jstr = json_decode(json)
    echo jstr
    " ⟹  {'year': 2023, 'animal': ['dog', 'cat', 'cow', 'fox', 'rat']}

    " /tmp/x1.json contains the following json
    {'year' : 2023, 
     'animal' : ['dog', 'cat', 'cow', 'fox', 'rat']
    }

    " join(readfile('/tmp/x1.json'), "\n") DOES NOT WORK ❌   
    " join(readfile('/tmp/x1.json'), '')   DOES NOT WORK EITHER ❌ 
    " join(readfile('/tmp/x1.json'), ' ')  DOES WORK  ✅, SPACE is important here. 
    let js = join(readfile('/tmp/x1.json', ' '))
    " js is dictionary
    echo js['year']
    " ⟹   2023
    echo js['animal']
    " ⟹  ['dog', 'cat', 'cow', 'fox', 'rat']