Safely evaluate math and boolean expressions.
$ composer require optimistex/math-expression
<?php
$e = new \optimistex\expression\MathExpression();
// basic evaluation:
$result = $e->evaluate('2+2');
// supports: order of operation; parentheses; negation; built-in functions
$result = $e->evaluate('-8(5/2)^2*(1-sqrt(4))-8');
// support of booleans
$result = $e->evaluate('10 < 20 || 20 > 30 && 10 == 10');
// support for strings and match (regexes can be like in php or like in javascript)
$result = $e->evaluate('"Foo,Bar" =~ /^([fo]+),(bar)$/i');
// previous call will create $0 for whole match match and $1,$2 for groups
$result = $e->evaluate('$2');
// create your own variables
$e->evaluate('a = e^(ln(pi))');
// or functions
$e->evaluate('f(x,y) = x^2 + y^2 - 2x*y + 1');
// and then use them
$result = $e->evaluate('3*f(42,a)');
// create external functions
$e->functions['foo'] = function() {
return "foo";
};
// and use it
$result = $e->evaluate('foo()');
?>This class can be used to safely evaluate mathematical expressions.
The class can take an expression in a text string and evaluate it by replacing values of variables and calculating the results of mathematical functions and operations.
It supports implicit multiplication, multivariable functions and nested functions.
It can be used to evaluate expressions from untrusted sources. It provides robust error checking and only evaluates a limited set of functions.
It could be used to generate graphs from expressions of formulae.
Use the Expression class when you want to evaluate mathematical or boolean
expressions from untrusted sources. You can define your own variables and
functions, which are stored in the object. Try it, it's fun!
Based on http://www.phpclasses.org/browse/file/11680.html, cred to Miles Kaufmann
$e->evalute($expr)
Evaluates the expression and returns the result. If an error occurs,
prints a warning and returns false. If $expr is a function assignment,
returns true on success.
$e->e($expr)
A synonym for $e->evaluate().
$e->vars()
Returns an associative array of all user-defined variables and values.
$e->funcs()
Returns an array of all user-defined functions.
$e->suppress_errors
Set to true to turn off warnings when evaluating expressions
$e->last_error
If the last evaluation failed, contains a string describing the error.
(Useful when suppress_errors is on).
Copyright 2005, Miles Kaufmann.
Copyright 2016, Jakub Jankiewicz
Copyright 2016, Konstantin Polyntsov
Version 2.0
For running tests just run $ make
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