How to Loop Over a JSON Array of Objects in Lua

Lua Automation IDE is a powerful tool that allows you to automate tasks and write scripts in Lua. One common task is working with JSON data, particularly when it comes to looping over an array of objects within the JSON structure. In this blog post, we will walk you through an example of how to accomplish this using Lua Automation IDE.

Let's say you have a JSON array of objects that contains information about people, such as their first name, last name, and age. Here's the example JSON array:

local jArray = [[
[
    {"FirstName":"Jane", "LastName":"Smith", "Age":"26"},
    {"FirstName":"Joe", "LastName":"Johnson", "Age":"46"},
    {"FirstName":"Kelsey", "LastName":"Winthrop", "Age":"36"}
] 
]]

To start, we need to parse the JSON array into a list of objects. We can achieve this by using the json.parse() function provided by Lua Automation IDE:

local obj = json.parse(jArray)

Now that we have the JSON array parsed into a list of objects, we can iterate over it using a for loop. In each iteration, we can access the properties of each object and perform any desired operations. In this case, let's print out each person's full name and age:

for k, v in pairs(obj) do
    ui.WriteLine(v.FirstName .. " " .. v.LastName .. " is " .. v.Age)
end

In the loop, k represents the index of the current object, and v represents the object itself. By using dot notation (v.FirstName, v.LastName, and v.Age), we can access the properties of each object and concatenate them to form a meaningful output.

By running the above code, you will see the following output in the console:

Jane Smith is 26
Joe Johnson is 46
Kelsey Winthrop is 36

In conclusion, Lua Automation IDE provides powerful features for working with JSON data, and looping over arrays of objects is just one example. By understanding the basics of parsing JSON and utilizing Lua's for loop, you can easily manipulate and extract information from JSON arrays in your Lua scripts.