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mission 2/Managers/ScopeManager.java

+package Managers;
+
+import java.util.Hashtable;
+import java.util.Stack;
+
+public class ScopeManager implements IManager {
+
+    public Stack<Hashtable<String, Integer>> getScopedVariables() {
+        return scopedVariables;
+    }
+
+    //This method works until we introduce classes down the line
+    //At that point classes will need their own scope manager somehow
+    private Stack<Hashtable<String, Integer>> scopedVariables = new Stack<>();
+
+    public void enterLocalScope() {
+        scopedVariables.push(new Hashtable<>());
+        System.out.println("Entered local scope");
+    }
+
+    public void leaveLocalScope() {
+        scopedVariables.pop();
+        System.out.println("Left local scope");
+    }
+
+    /**
+     * Gets all currently accessible variables.
+     */
+    public Hashtable<String, Integer> getAllVariables() {
+        Hashtable<String, Integer> output = new Hashtable<>();
+        for (Hashtable<String, Integer> scopeLevel : scopedVariables) {
+            output.putAll(scopeLevel);
+        }
+        return output;
+    }
+
+    public void modifyVariable(String varName, int newValue) {
+        //Locate the variable, if it exists modify it otherwise create it in the current scope
+        for (Hashtable<String, Integer> scopeLevel : scopedVariables) {
+            //It exists
+            if (scopeLevel.containsKey(varName)) {
+                scopeLevel.replace(varName, newValue);
+                return;
+            }
+        }
+        //It doesn't exist
+        scopedVariables.peek().put(varName, newValue);
+    }
+
+    public void removeVariable(String varName) {
+        for (Hashtable<String, Integer> scopeLevel : scopedVariables) {
+            if (scopeLevel.containsKey(varName)) {
+                scopeLevel.remove(varName);
+            }
+        }
+    }
+
+}