diff --git a/src/main/java/de/maishai/typedast/typedclass/TypedClass.java b/src/main/java/de/maishai/typedast/typedclass/TypedClass.java
index aec8ef4..9c0ffea 100644
--- a/src/main/java/de/maishai/typedast/typedclass/TypedClass.java
+++ b/src/main/java/de/maishai/typedast/typedclass/TypedClass.java
@@ -98,37 +98,20 @@ public class TypedClass implements TypedNode {
         return type;
     }
 
-    public boolean isParameterWitNameInMethod(String parameterName) {
-        for (TypedMethod m : typedMethods) {
-            for (TypedParameter p : m.getTypedParameters()) {
-                if (p.getParaName().equals(parameterName)) {
-                    return true;
-                }
-            }
-        }
-        return false;
+    public boolean isParameterWitNameInCurrentMethod(String parameterName) {
+        return this.getCurrentMethod().getTypedParameters().stream().anyMatch(parameter -> parameter.getParaName().equals(parameterName));
     }
 
-    public boolean isParameterWitNameInConstructor(String parameterName) {
-        for (TypedConstructor c : typedConstructors) {
-            for (TypedParameter p : c.getTypedParameters()) {
-                if (p.getParaName().equals(parameterName)) {
-                    return true;
-                }
-            }
-        }
-        return false;
+    public boolean isParameterWitNameInCurrentConstructor(String parameterName) {
+        return this.getCurrentConstructor().getTypedParameters().stream().anyMatch(parameter -> parameter.getParaName().equals(parameterName));
     }
 
     public Type getParameterTypeInCurrentMethod(String parameterName) {
-        for (TypedMethod m : typedMethods) {
-            for (TypedParameter p : m.getTypedParameters()) {
-                if (p.getParaName().equals(parameterName)) {
-                    return p.getType();
-                }
-            }
-        }
-        return null;
+        return getCurrentMethod().getTypedParameters().stream().filter(parameter -> parameter.getParaName().equals(parameterName)).findFirst().get().getType();
+    }
+
+    public Type getParameterTypeInCurrentConstructor(String parameterName) {
+        return getCurrentConstructor().getTypedParameters().stream().filter(parameter -> parameter.getParaName().equals(parameterName)).findFirst().get().getType();
     }
 
     public boolean isMethodOfCurrentClass(String methodName) {
@@ -149,15 +132,6 @@ public class TypedClass implements TypedNode {
         return null;
     }
 
-    public Type getParameterTypeInCurrentConstructor(String parameterName) {
-        for (TypedParameter p : currentConstructor.getTypedParameters()) {
-            if (p.getParaName().equals(parameterName)) {
-                return p.getType();
-            }
-        }
-        return null;
-    }
-
     public boolean isThereField(String fieldName) {
         for (TypedDeclaration f : typedDeclarations) {
             if (f.getName().equals(fieldName)) {
diff --git a/src/main/java/de/maishai/typedast/typedclass/TypedFieldVarAccess.java b/src/main/java/de/maishai/typedast/typedclass/TypedFieldVarAccess.java
index 0bcc21a..3ab9a9e 100644
--- a/src/main/java/de/maishai/typedast/typedclass/TypedFieldVarAccess.java
+++ b/src/main/java/de/maishai/typedast/typedclass/TypedFieldVarAccess.java
@@ -84,7 +84,7 @@ public class TypedFieldVarAccess implements TypedExpression {
     }
 
     private Type checkMethodVariableType(TypedProgram typedProgram) {
-        if (typedProgram.getCurrentClass().isParameterWitNameInMethod(name)) {
+        if (typedProgram.getCurrentClass().isParameterWitNameInCurrentMethod(name)) {
             type = typedProgram.getCurrentClass().getParameterTypeInCurrentMethod(name);
         } else if (typedProgram.getCurrentClass().getCurrentMethod().isLocalVariablePresent(name)) {
             type = typedProgram.getCurrentClass().getCurrentMethod().getLocalVariableType(name);
diff --git a/src/main/java/de/maishai/typedast/typedclass/TypedMethod.java b/src/main/java/de/maishai/typedast/typedclass/TypedMethod.java
index 5754dac..674f4e9 100644
--- a/src/main/java/de/maishai/typedast/typedclass/TypedMethod.java
+++ b/src/main/java/de/maishai/typedast/typedclass/TypedMethod.java
@@ -52,6 +52,7 @@ public class TypedMethod implements TypedNode {
     public void convertToTypedBlock(TypedProgram typedProgram, Method unTypedMethod) {
         typedBlock = new TypedBlock(typedProgram, unTypedMethod.block());
         typeCheck(typedProgram);
+        localVariables.clear();
     }
 
     public boolean isLocalVariablePresent(String localVarName) {
diff --git a/src/main/java/de/maishai/typedast/typedclass/TypedParameter.java b/src/main/java/de/maishai/typedast/typedclass/TypedParameter.java
index 6cc752a..67d106b 100644
--- a/src/main/java/de/maishai/typedast/typedclass/TypedParameter.java
+++ b/src/main/java/de/maishai/typedast/typedclass/TypedParameter.java
@@ -35,11 +35,11 @@ public class TypedParameter implements TypedNode {
     public Type typeCheck(TypedProgram typedProgram) {
 
         if (typedProgram.getCurrentClass().isCurrentMethodPresent()) {
-            if (typedProgram.getCurrentClass().isParameterWitNameInMethod(paraName)) {
+            if (typedProgram.getCurrentClass().isParameterWitNameInCurrentMethod(paraName)) {
                 throw new RuntimeException("Parameter " + paraName + " already exists");
             }
         } else if (typedProgram.getCurrentClass().isCurrentConstructorPresent()) {
-            if (typedProgram.getCurrentClass().isParameterWitNameInConstructor(paraName)) {
+            if (typedProgram.getCurrentClass().isParameterWitNameInCurrentConstructor(paraName)) {
                 throw new RuntimeException("Parameter " + paraName + " already exists");
             }
         }