arithmexp
arithmexp is a powerful mathematical expression parser and evaluator library for PHP with support for variable substitution, constant declaration, deterministic and non-deterministic function registration, and more.
Tip
Try out arithmexp parser on the demo site!
Installation with composer
composer require muqsit/arithmexp
Evaluating a mathematical expression
To evaluate a mathematical expression, create a Parser and invoke Parser::parse() with an expression string to obtain a reusable Expression object.
Expression::evaluate() returns the value of the expression.
$expression = $parser->parse("2 + 3");
var_dump($expression->evaluate()); // int(5)
$expression = $parser->parse("mt_rand()");
var_dump($expression->evaluate()); // int(1370501507)
var_dump($expression->evaluate()); // int(1522981420)
Variables may be substituted at evaluation-time by passing an array value to Expression::evaluate().
var_dump($expression->evaluate(["x" => 2, "y" => 3])); // int(5)
var_dump($expression->evaluate(["x" => 1.5, "y" => 1.5])); // float(3)
$expression = $parser->parse("a > b or c");
var_dump($expression->evaluate(["a" => 1, "b" => 2, "c" => true])); // bool(true)
The return value type of the evaluation is consistent with that of PHP's--int + int returns an int value, while float + int|float returns a float value.
bool + bool returns an int value, while int || int returns a bool value.
Note
Check out the wiki for documentation notes and further implementation details.