How to Calculate arithmetic operators in strings via PHP

calcStr.beta.php

<?php

function calc($str)
{ 
	$compute = create_function('', 'return (' . trim($str) . ');' );
	return $compute();
}

# Demonstration
$string = " (5 - 1) * (6 / 2 + 1) ";
$output = calc($string);
var_dump($output);	// int(16)

calcStr.final.php

<?php

# So we can merge two other tricks into this one, for more assurance

function calc($str)
{ 
    $compute = create_function('', 'return (' . trim($str) . ');' );
	return 0 + $compute();
}
 
$string = " (5 - 1) * (6 / 2 + 1) ";
$output = calc($string);
var_dump($output);	// int(16)

toInteger.php

<?php

# How to convert a string number to Integer?
# This will do the trick ;)

function toInteger($str)
{
    return 0 + $str;   
}

# Demonstration
$string = "-8";
$output = toInteger($string);
var_dump($output);    // int(-8)