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JSON Arrays

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Arrays as JSON Objects #

Example #

[ "Ford", "BMW", "Fiat" ]

Arrays in JSON are almost the same as arrays in JavaScript.

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]; }

Or you can use a for loop:

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" ] } ] }

To access arrays inside arrays, use a for-in loop for each array:

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];

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