npm install safe-expr-eval

import { Parser } from 'safe-expr-eval';

const parser = new Parser();
const expr = parser.parse('2 * x + 1');

console.log(expr.evaluate({ x: 3 })); // 7
console.log(expr.evaluate({ x: 10 })); // 21

import { evaluate } from 'safe-expr-eval';

const result = evaluate('10 + 5 * 2');

console.log(result); // 20

import { compile } from 'safe-expr-eval';

const fn = compile('price * quantity * (1 - discount)');

console.log(
  fn({
    price: 100,
    quantity: 2,
    discount: 0.1
  })
); // 180

+  -  *  /  %

==  !=  >  <  >=  <=

and  or  not
&&   ||   !

Numbers   → 42, 3.14
Strings   → "hello"
Booleans  → true, false
Variables → price, user.name

const parser = new Parser();

parser.functions.max = Math.max;
parser.functions.min = Math.min;
parser.functions.round = Math.round;

const expr = parser.parse(
  'round(max(a, b) * 1.5)'
);

console.log(
  expr.evaluate({
    a: 10,
    b: 20
  })
); // 30

const parser = new Parser();

parser.consts.PI = Math.PI;
parser.consts.TAX_RATE = 0.15;

const expr = parser.parse(
  'price * (1 + TAX_RATE)'
);

console.log(
  expr.evaluate({
    price: 100
  })
); // 115

new Parser()

parser.parse(expression)

parser.evaluate(expression, variables?)

parser.functions

parser.consts

evaluate(expression, variables?)

compile(expression)

npm test

npm run test:coverage

GitHub: https://github.com/