Merge pull request #28 from phpfui/support_for_double_quoted_strings

Support for double quoted strings

1 files changed, 5 insertions, 1 deletions

diff --git a/src/NXP/Classes/Calculator.php b/src/NXP/Classes/Calculator.php
index b584d69..bfa7015 100644
--- a/src/NXP/Classes/Calculator.php
+++ b/src/NXP/Classes/Calculator.php
@@ -13,6 +13,7 @@ namespace NXP\Classes;
 use NXP\Classes\Token\InterfaceOperator;
 use NXP\Classes\Token\TokenFunction;
 use NXP\Classes\Token\TokenNumber;
+use NXP\Classes\Token\TokenString;
 use NXP\Classes\Token\TokenVariable;
 use NXP\Exception\IncorrectExpressionException;
 use NXP\Exception\UnknownVariableException;
@@ -32,11 +33,14 @@ class Calculator
      */
     public function calculate($tokens, $variables)
     {
-        $stack = array();
+        $stack = [];
         foreach ($tokens as $token) {
             if ($token instanceof TokenNumber) {
                 array_push($stack, $token);
             }
+            if ($token instanceof TokenString) {
+                array_push($stack, $token);
+            }
             if ($token instanceof TokenVariable) {
                 $variable = $token->getValue();
                 if (!array_key_exists($variable, $variables)) {