How to access a JSON array directly from url

Question

I am new to javascript and I have a Json Array in a url like below;

[{"year":2015,"month":4,"day":1,"num":0,"time":"2015-04-01","hour":0,"zone":3,"state1":2137,"state2":249,"state3":1810,"state4":30,"state5":0},....]

I want to access the state1 value and assign that value to the variable which I have.How can I do that?(Is parsing necessary or are there any methods there that we can directly access the JSON object in the URL).I am sorry if I asked anything wrong.

Answer 1

You can use jQuery getJSON() function :

$.getJSON(' localhost:8080/dataurl', function(data) {
  //data is the JSON string
  var jsonObj = JSON.parse(data);    
});

Now, Below are the methods to parse the jsonObj to get the state1.

Using array map() method :

var jsonObj = [
                {
                  "year":2015,
                  "month":4,
                  "day":1,
                  "num":0,
                  "time":"2015-04-01",
                  "hour":0,
                  "zone":3,
                  "state1":2137,
                  "state2":249,
                  "state3":1810,
                  "state4":30,
                  "state5":0
                },
                {
                  "year":2016,
                  "month":12,
                  "day":1,
                  "num":0,
                  "time":"2015-04-01",
                  "hour":0,
                  "zone":3,
                  "state1":2474,
                  "state2":250,
                  "state3":1811,
                  "state4":31,
                  "state5":0
                }
              ];

var state1arr = jsonObj.map(function(item) {
  return item.state1;
});

console.log(state1arr);

using for...in loop :

var jsonObj = [
                {
                  "year":2015,
                  "month":4,
                  "day":1,
                  "num":0,
                  "time":"2015-04-01",
                  "hour":0,
                  "zone":3,
                  "state1":2137,
                  "state2":249,
                  "state3":1810,
                  "state4":30,
                  "state5":0
                },
                {
                  "year":2016,
                  "month":12,
                  "day":1,
                  "num":0,
                  "time":"2015-04-01",
                  "hour":0,
                  "zone":3,
                  "state1":2474,
                  "state2":250,
                  "state3":1811,
                  "state4":31,
                  "state5":0
                }
              ];

var state1arr = [];
for (var i in jsonObj) {
  state1arr.push(jsonObj[i].state1);
}

console.log(state1arr);