calc

Calculates mathematical expressions

The calc function takes a string argument and returns the value of the resulting calculation.

Install

npm install @motardo/calc

Usage

var calc = require("@motardo/calc");

calc("1+2")          // 3
calc("-1 / 2")       // -0.5
calc("2 + 3 * 4")    // 14
calc("(2+3)*4")      // 20
calc("5^2")          // 25

Demo

Try it out at https://motardo.github.io/calc/web/index.html

Testing

Run the tests with:

npm test

About

calc uses the shunting yard algorithm and two separate stacks, one for numerical values, and one for operators. The operators currently supported are + - * / and ^. Parenthesis can be used to override operator precedence.

TODO

• Add support for shorthand scientific notation as in 1e9 for 1 billion
• Add support for trigonometric functions
• Add support for log and ln notation

Bugs

Bug reports and contributions are welcome. Open an issue on github or email the author at nswilson@gmail.com