API Calculator

This is a simple Express API that provides calculate endpoints for basic math operations.

What?

A calculator that consumes url params and returns results server side, for whatever reason...

Adds, subtracts, divides and multiplies

Accepts arbitrary lengths of operations and numbers, for example:

/calculate/add/10/15/subtract/5/divide/2 -> 10

Endpoints

GET /calculate/:operator/:values

Performs a calculation based on the provided operator and values.

• :operator - The arithmetic operator to use. Can be add, subtract, multiply, or divide.
• :values - The numeric values to calculate, separated by /.

Example Request(s)

GET /calculate/add/1/2/3 -> 6

GET /calculate/subtract/10/5 -> 5

GET /calculate/divide/50/5 -> 10

GET /calculate/add/20/30/subtract/20/add/10/divide/2/multiply/2 -> 40

Code Overview

index.js

The main Express app file.

• Sets up the Express app and its middleware.
• Defines the /calculate route and handler.
• Calls helper functions to parse the request and perform the calculation.
• Handles errors with a custom error handler middleware.

helpers/index.js

Contains helper functions used by index.js.

• convert_to_operation - Parses the request params into an array of operation/values arrays.
• calculate_main - Performs the calculations by iterating through the operations.
• error_handler - Custom error handler middleware.

Contains the recursive arithmetic functions, used recursion to practice using recursion, to practice using recursion...

• add()
• subtract()
• multiply()
• divide()

Usage

BUN

bun install
bun run dev

NPM

npm install
npm run dev

The server will start on port 8080.

To calculate 2 + 3 - 5, make a request:

GET /calculate/add/2/3/subtract/5

The result will be returned in the JSON response.