Parsing and serializing JSON
JSON is a widely used data interchange format. It is a human-readable, but also easily machine-readable.
To parse a JSON string, you can use the builtin JSON.parse function. The value is returned as a JavaScript object.
const text = `{
"hello": "world",
"numbers": [1, 2, 3]
}`;
const data = JSON.parse(text);
console.log(data.hello);
console.log(data.numbers.length);To turn a JavaScript object into a JSON string, you can use the builtin JSON.stringify function.
const obj = {
hello: "world",
numbers: [1, 2, 3],
};
const json = JSON.stringify(obj);
console.log(json);
// {"hello":"world","numbers":[1,2,3]}By default JSON.stringify will output a minified JSON string. You can customize this by specifying an indentation number in the third argument.
const json2 = JSON.stringify(obj, null, 2);
console.log(json2);
// {
// "hello": "world",
// "numbers": [
// 1,
// 2,
// 3
// ]
// }Run this example locally using the Deno CLI:
deno run https://docs.deno.com/learn/examples/parsing-serializing-json.ts