anthonykoch / mathparser

A math parser that compiles and evaluates mathematical expressions

Math parser

This is a part of a project I made for a dribbble challenge I put up on codepen. The challenge was to make a calculator, which can be found here. The code for the calculator was written in a very short amount of time (2-3 days), and is not the most efficiently written. Also, it doesn't take floating point errors into account.

Supported expressions

• Primary expression

  • Number literal (does not support exponents)

• Unary expressions

  • Unary plus e.g. "+42 + 6" or "42 * +6"
  • Unary minus e.g. "-42 + 6" or "42 + -6"

• Exponents and root

  • Exponents through "**" e.g. "4 ** 4" evaluates to 256
  • nth root.

• Multiplicative expressions

  • Division e.g. "20 / 4"
  • Multiplication e.g. "3 * 2"

• Additive expressions

  • Addition e.g. "2 + 6"
  • Subtraction e.g. "6 - 4"

• Parentheses

Examples

const { MathParser } = require('./index');

const expression = '3 * 2';
const result = MathParser.eval(expression);
console.log(result); // 6

Todo

• More tests

• Change the root character to "yroot"

• Add support for auto closing parens.