JSON-to-data conversion in JavaScript

Using the JSON.parse method, you can convert JSON to a JavaScript data structure. Let's look at an example.

Let's say we have a string containing an array in JSON format:

let json = '[1, 2, 3, 4, 5, "a", "b"]';

Let's convert our string to an array:

let arr = JSON.parse(json);

If the string contains invalid JSON, our method will throw an error:

let json = '[1, 2, 3, 4, 5,]'; // invalid JSON
let arr = JSON.parse(json);    // throws an error

Given a JSON string containing an array of numbers:

let json = '[1,2,3,4,5]';

Convert this string to a real JavaScript array and find the sum of the numbers of this array.

Given a JSON string containing an object with data:

let json = `{
	"data1": [1,2,3],
	"data2": [4,5,6],
	"data3": [7,8,9]
}`;

Find the sum of numbers from the given data.

Given a JSON string containing usernames:

let json = '["user1","user2","user3","user4","user5"]';

Output these names as an ul list.

Given a JSON string, containing an array with employees data:

let json = `[
	{
		"name": "user1",
		"age": 25,
		"salary": 1000
	},
	{
		"name": "user2",
		"age": 26,
		"salary": 2000
	},
	{
		"name": "user3",
		"age": 27,
		"salary": 3000
	}
]`;

Display these employees in the form of an HTML table.