PHP code example of optimistex / math-expression

1. Go to this page and download the library: Download optimistex/math-expression library. Choose the download type require.

2. Extract the ZIP file and open the index.php.

3. Add this code to the index.php. 
    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

optimistex / math-expression example snippets


    
      $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()');