Starting to integrate Spring 2026 exam into solutions.

Author: aubertc

source/code/projects/ReferenceMethods/ReferenceMethods/Program.cs

@@ -4,6 +4,41 @@ class Program
 {
   static void Main(string[] args)
   {
+    // Example for NameChange
+            static void NameChange(ref string name, string newname, out string oldname){
+          oldname = name;
+          name = newname;
+        }    
+        
+      string name = "Smith", oldname;
+      Console.WriteLine("Enter new name.");
+      NameChange(ref name, Console.ReadLine(), out oldname);
+      Console.WriteLine($"New name: {name}\nOld name: {oldname}");
+      
+      /*
+      // Example for Test method
+
+        static void Test(int a, out int b){
+            if (b < 0) { b = a; }
+            else { b++;}
+        }
+      */
+    
+    // SafeLength
+      static int SafeLength<T>(T[] aP){
+        int ans;
+        if (aP == null) ans = -1;
+        else ans = aP.Length;
+        return ans;
+      }
+      
+      int[] test1 = null;
+      Console.WriteLine(SafeLength(test1));
+      char[] test2 = {'a', 'b'};
+      Console.WriteLine(SafeLength(test2));
+      
+      
+    
     // Example for AddRev
     int x0 = 4,
       y0 = 3;

source/solutions/data/1darrays.md

@@ -897,7 +897,7 @@ Those two problems are related to [binary search](./lectures/collections/search#
     </details>
     #. Explain why this implementation is incorrect, and how it can be fixed.
     <details><Summary>Solution</summary>
-    The problem is that `mid` will never reach `arrayP.Length -1`.
+    The problem is that what we use for `mid` (`(sta + end) / 2`) will never reach `arrayP.Length -1`.
     Indeed, we will have an expression equivalent to `((arrayP.Length -2) - arrayP.Length-1) / 2` (for example, as above, `(10 + 11) / 2`) that will never be rounded up to `arrayP.Length-1` (in our example, `11`), but always truncated.
 
     To fix this implementation, instead of `end = (sta + end) / 2;`, we should have  `end = ((sta + end) / 2) + 1;`.

source/solutions/oop/references.md

@@ -79,6 +79,24 @@ tags:
     `c` holds `'*'`, `d` holds `%`.
     </details>
 
+#. Consider the following method:
+
+    ```
+    static void NameChange(ref string nameP, string newnameP, out string oldnameP){
+        oldnameP = nameP;
+        nameP = newnameP;
+    }        
+    ```
+    
+    <details><summary>Solution</summary>
+    
+    </details>
+
+    
+    Assume given a `string` `name` variable containing a value. Write a short program (possibly declaring additional variables) that
+    #. Asks the user their new name,
+    #. Calls the `NameChange` method with appropriate arguments,
+    #. Displays the new name and the old name.
 
 ## Problems