get variable from JSON Array

Question

I want to get the key from the JSON Array? This is my JSON Array

****JAVASCRIPT****
var employees = [
                 { "firstName":"John" , "lastName":"Doe" }, 
                 { "firstName":"Anna" , "lastName":"Smith" }, 
                 { "firstName":"Peter" , "lastName": "Jones" }
               ];

From this JSON I need the result key. I mean "firstName", "lastName", not John, Anna, Peter Please help to get the keys from JSON.

Answer 1

Try this:

http://jsfiddle.net/NJMyD/1072/

var employees = '[{"firstName":"John","lastName":"Doe" },{"firstName":"Anna","lastName":"Smith" },{"firstName":"Peter","lastName":"Jones"}]';

var myData = JSON.parse(employees);

$(document).ready(function() {
    $.each(myData, function() {
        $('<li>' + this.firstName + ' ' + this.lastName + '</li>').appendTo("#groups");
    });
});

Answer 2

Try this

var employees = [
             { "firstName":"John" , "lastName":"Doe" }, 
             { "firstName":"Anna" , "lastName":"Smith" }, 
             { "firstName":"Peter" , "lastName": "Jones" }
           ]; //your array

for(var i in employees)
{
var fname=employees[i].firstName
var lname=employees[i].lastName
console.log(fname) //all first names
console.log(lname) //all last names
}

Fiddle

http://jsfiddle.net/8TB6Z/

Answer 3

I think you need the key . Object has a prototype keys which returns an Array of keys in an Object

Object.keys(employees); // returns ["firstName", "lastName"]

Also

for(i in employees){
var key = i;
var val = employees[i];
for(j in val)
    {
    var sub_key = j;
    var sub_val = val.j;
    console.log(sub_key);
    }
}

Answer 4

Try this:

var employees = [
    { "firstName":"John" , "lastName":"Doe" }, 
    { "firstName":"Anna" , "lastName":"Smith" }, 
    { "firstName":"Peter" , "lastName": "Jones" }
];
$.each(employees,function(f,n){                    
    $.each(n,function(ff,nn){
        console.log("field:"+ff+" value:"+nn);                        
    });
}); 

Fiddle here:

Hope it helps you.

Answer 5

If you are saving javascript in external file, save as filename.json

var employees = [
                 { "firstName":"John" , "lastName":"Doe" }, 
                 { "firstName":"Anna" , "lastName":"Smith" }, 
                 { "firstName":"Peter" , "lastName": "Jones" }
               ];

Then improt filename.json in webpage using jquery as //jquery plugin must be added first

$(document).ready(function(){
$.getJSON("filename.json",function(result){
alert(result[0].firstname + result[0].lastname);
});
});