Evaluate Numerical Expressions

Installation

npm install --save eval-num-expr

Usage

importevalExprfrom"eval-num-expr";constvalue=evalExpr("100 + 3 * 55 + 73 - 73 * 18%");// value = 324.86// With Invalid Expressions handlingtry{constvalue=evalExpr("100 + (3 * 55");}catch(e){// Will throw an exception for invalid expressionsconsole.error(e.message);}

You can use basic operations (e.g. +, -, *, /, %, ^ etc.) in you expressions.

Examples

• 175 + 40 + 18% = 253.7
• 10 + (100 - 100 * 18%) * 5 + 40 / 20 = 422

NOTE: Floating points must be handled carefully. Use Number(<number>).toFixed(<digits>) to fix the digits after decimal point.

Api

This package supports TypeScript.

evalExpr

This is the default and only export from this package.

/** * Evaluate numeric mathematical expression * @param string expression - The expression to evaluate ("24 + 65 * 3 - 48") * @return number - The evaluated value. * * @throws Will throw an error if the expression in invalid. * * NOTE: When passing floating points, please handle the digits after decimal point * e.g. 2 - 1.1 leads to 0.8999999999999999 intead of .9 */evalExpr(expressions: string)