Reverse Polish Notation (RPN) Calculator
This is a Reverse Polish Notation (RPN) calculator for the command line.
How to Use This Calculator
Clone this repo to your machine and play along!
To use RPN Calculator in the command line, you must have Node installed on your machine as well as node_modules in the repository.
-- In your terminal --
- To check for Node, simply type:
node -v - To install node_modules, simple type:
npm install
You may write each calculation directly in the console after running the file.
Follow the instructions in the program. Here are the steps to get started:
node index.js- Input your calculations such as
5 5 5 8 + + - - The program runs (and ends) according to your input!
Technical Architecture
The general logic behind evaluating the RPN:
- Create new Array and let values be scoped within evaluation function
- Set values to user input and split the new array between numbers
- Set new function Calculate() to take in user input
- Loop through all items of user input
- If item is not an operator value, then push these evaluated values to a stack
- Else, if item is a numeric value, then pop two numerics from the stack and evaluate based on the switch statement cases
Improvements to be Made
The following items could be made as improvements:
- Instead of using eval (since it is not secure), there could be a forEach loop that takes in the item, index, and array.
- This could probably use additional testing features for edge cases, such as ^ and decimal values
- The program ends after one use. This could be improved by continually asking the user for calculations until they quit the program manually.