diff --git a/src/Calc.php b/src/Calc.php
index 98cd58e..09efa38 100644
--- a/src/Calc.php
+++ b/src/Calc.php
@@ -33,8 +33,6 @@ final class Calc
 
     private $variables = [];
 
-    //protected $allowedPhpFunctions = false;
-
     /**
      * @param integer $scale
      */
@@ -54,7 +52,7 @@ public function evaluate(array $tokens, array $variables = [])
     {
         $stack = new SplStack;
 
-        //var_dump($tokens);
+        $this->defineVars($variables);
 
         foreach ($tokens as $token) {
             if ($token->isNumber()) {
@@ -170,6 +168,23 @@ public function defineVar($name, $value)
         return $this;
     }
 
+    /**
+     * Define new variables.
+     * <br>
+     * Array format ['varName' => 'varValue', ...]
+     *
+     * @param array $variables
+     * @return \Sufir\Calc\Calc
+     */
+    public function defineVars(array $variables = [])
+    {
+        foreach ($variables as $name => $value) {
+            $this->defineVar($name, $value);
+        }
+
+        return $this;
+    }
+
     /**
      * @param string $operator
      * @param integer|float $firstOperand
diff --git a/src/Token/OperatorToken.php b/src/Token/OperatorToken.php
index b035eb1..ccefe71 100644
--- a/src/Token/OperatorToken.php
+++ b/src/Token/OperatorToken.php
@@ -44,8 +44,6 @@ public function getPriority($assoc = 'left')
                     return 2;
                 case '+':
                     return 1;
-                default:
-                    return 0;
             }
         } else {
             switch ($this->value) {
@@ -57,8 +55,6 @@ public function getPriority($assoc = 'left')
                 case '+':
                 case '-':
                     return 1;
-                default:
-                    return 0;
             }
         }
     }
diff --git a/tests/CalcTest.php b/tests/CalcTest.php
index bc4cf2e..be96736 100644
--- a/tests/CalcTest.php
+++ b/tests/CalcTest.php
@@ -51,9 +51,7 @@ public function testEvaluate(
             $this->calc->registerFunction($functionName, $functionBody);
         }
 
-        foreach ($variables as $name => $value) {
-            $this->calc->defineVar($name, $value);
-        }
+        $this->calc->defineVars($variables);
 
         $result = $this->calc->evaluate($converted);
 
diff --git a/tests/TokenTest.php b/tests/TokenTest.php
index 6579311..bf13f9b 100644
--- a/tests/TokenTest.php
+++ b/tests/TokenTest.php
@@ -177,7 +177,7 @@ public function testOperatorToken($expr)
         $this->assertInternalType('boolean', $operator->isRightAssoc());
         $this->assertInternalType('boolean', $operator->isLeftAssoc());
         $this->assertNotEquals($operator->isLeftAssoc(), $operator->isRightAssoc());
-        $this->assertGreaterThan(0, $operator->getPriority());
+        $this->assertGreaterThan(0, $operator->getPriority('left'));
         $this->assertGreaterThan(0, $operator->getPriority('right'));
 
         return $operator;