Sort a PHP JSON nested array in ascending order with usort according to a key value

Question

I have the following JSON array in my PHP

 {
    "responseHeader": {
        "type": "Places",
        "status": "200",
        "message": "Places fetched"
    },
    "Places_nearby": [{
            "place_name": "blueblue",
            "place_rating": "5"


        },
        {
            "place_name": "qwer",
            "place_rating": "10"


        },
        {
            "place_name": "mvb",
            "place_rating": "0.6"


        },
        {
            "place_name": "tyu",
            "place_rating": "25"


        },
        {
            "place_name": "erty",
            "place_rating": "1"


        },

        {
            "place_name": "Malabar Adukkala",
            "place_rating": "7"

        }
    ],
    "Google_places_most_rated": [{

            "place_name": "Malabar Adukkala",
            "place_rating": "5"


        },


        {
            "place_name": "Malabar Adukkala",
            "place_rating": "5"


        }

    ]


} 

I need to sort the "Places_nearby" array inside it by increasing value of "place_rating".

What I did was decoding the JSON in my code,

json_decode($json,true)

And then using usort as follows

 function sortfunction($a, $b) {
return strcasecmp($a['place_rating'], $b['place_rating']);

}

usort($data['Places_nearby'], 'sortfunction');

But nothing happens.

How can I rewrite usort function, or do I want to write my custom function to sort the array? I thought that if PHP had some internal sporting mechanisms, that would be faster than other methods I can write.

PS : I have already tried solutions that are mentioned in other SO answers, but they seems to be not working with my case.

Answer 1

Here we are using usort for sorting.

Try this code snippet here

usort($array["Places_nearby"],function($value1,$value2){
  return  $value1["place_rating"]>$value2["place_rating"];
});
print_r($array);