JSON Arrays
Arrays as JSON Objects
Example
[ "Ford", "BMW", "Fiat" ]
In JSON, array values must be of type string, number, object, array, boolean or null.
In JavaScript, array values can be all of the above, plus any other valid JavaScript expression, including functions, dates, and undefined.
Arrays in JSON Objects
Arrays can be values of an object property:Example
{
"name":"John",
"age":30,
"cars":[ "Ford", "BMW", "Fiat" ]
}
Accessing Array Values
You access the array values by using the index number:Example
x = myObj.cars[0];
Looping Through an Array
You can access array values by using a for-in loop:Example
for (i in myObj.cars) {
x += myObj.cars[i];
}
Example
for (i = 0; i < myObj.cars.length; i++) {
x += myObj.cars[i];
}
Nested Arrays in JSON Objects
Values in an array can also be another array, or even another JSON object:Example
myObj = {
"name":"John",
"age":30,
"cars": [
{ "name":"Ford", "models":[ "Fiesta", "Focus", "Mustang" ] },
{ "name":"BMW", "models":[ "320", "X3", "X5" ] },
{ "name":"Fiat", "models":[ "500", "Panda" ] }
]
}
Example
for (i in myObj.cars) {
x += "<h1>" + myObj.cars[i].name + "</h1>";
for (j in myObj.cars[i].models) {
x += myObj.cars[i].models[j];
}
}
Modify Array Values
Use the index number to modify an array:Example
myObj.cars[1] = "Mercedes";
Delete Array Items
Use the delete keyword to delete items from an array:Example
delete myObj.cars[1];