calculate

TABLE OF CONTENTS

• Definition
• Parameters
• Returns
• Examples
• Remarks

Compute a mathematical formula

Definition

number calculate(string $expression, object $variables)

Computes a given mathematical formula using the provided variables.

Parameters

string $expression

A string representing a mathematical formula to be calculated. Consists of variables, named by the users, as well as operators and base functions.

Operators

• Addition: +
• Subtraction: –
• Multiplication: *
• Division: /
• Modulo: %
• Exponentiation: ^
• Negation: !
• Equality: ==
• Less than: <
• Greater than: >
• Less or equal to: <=
• Greater or equal to: >=
• Inequality: !=
• Parentheses: ()

Base functions

object $variables

An object where the keys represent variable names, and the values represent the values to be inserted into the formula in place of their respective variables.

Returns

number

The result of the formula.

Examples

{  
  intSum: calculate('a+b', {"a": 10, "b": 20}),
  numStringSum: calculate('a+b', {"a": '10', "b": '20'}),
  floatSum: calculate('a+b', {"a": 10.5, "b": 20}), 
  intSubtract: calculate('a-b', {"a": 10, "b": 20}),
  addMultiply: calculate('(a+b)\_10', {"a": 10, "b": 20}),
  sin: calculate('sin(a)\_3', {"a": 45}),
  noVariables: calculate('(10+20)/10', null),
  logn: calculate('logn(4, 2)',`null`),
  round: calculate('round(1.5)',`null`),
  nullArg: calculate('a+b', null),                          // Error
  objArg: calculate('a+b', {}),                             // Error
  stringSum: calculate('10+b', {"b": 'aSimpleString'})      // Error
}

{  
  "intSum": 30.0,
  "numStringSum": 30.0,
  "floatSum": 30.5,
  "intSubtract": -100,
  "addMultiply": 300.0,
  "sin": 2.552710573602355,
  "noVariables": 3.0,
  "logn": 2.0,
  "round": 2.0
}

Remarks

The variables must be provided even if the formula doesn't depend on any variables, like random() or (1+2). Note that you can simply pass null in this case as the variable. Returns "NaN" on mathematically invalid input, like a negative number as an argument to the log function. Only numbers and strings with number formatting are accepted as arguments.