How to Build a Simple JSON Parser in JavaScript
JSON, or JavaScript Object Notation, is a lightweight data-interchange format that is easy to read and write. We often encounter it while working with APIs and server-side data. Let's delve into the intricacies of parsing JSON, step by step.
Addressing Edge Cases: Simple Types and Errors
Why Handle Edge Cases?
Before we even think about parsing complex objects or arrays, let's handle some edge cases. These are simple data types or even errors that might make our parser trip if we don't deal with them first.
How to Handle?
We'll use if statements to check if our input string is one of these edge cases and return the corresponding JavaScript object.
JAVASCRIPT
1if (input === "" || input[0] === "'") {
2 throw Error("Invalid JSON string");
3}
4if (input === "null") {
5 return null;
6}
7if (input === "{}") {
8 return {};
9}
10if (input === "[]") {
11 return [];
12}
13if (input === "true") {
14 return true;
15}
16if (input === "false") {
17 return false;
18}