Update chapter 3

Author: ShiqiYu

week03/Lecture03.pptx

@@ -0,0 +1,34 @@
+#include <iostream>
+
+using namespace std;
+
+float mysquare(float value)
+{
+    float result = 0.0f;
+
+    if(value >= 1.0f || value <= 0)
+    {
+        cerr << "The input is out of range." << endl;
+        goto EXIT_ERROR;
+    }
+    result = value * value;
+    return result;
+
+  EXIT_ERROR:
+    //do sth such as closing files here
+    return 0.0f;
+}
+
+int main()
+{
+    float value;
+    cout << "Input a floating-point number." << endl;
+    cin >> value;
+
+    float result = mysquare(value);
+
+    if (result > 0)
+        cout << "The square is " << result << "." << endl;
+
+    return 0;
+}

week03/examples/goto.cpp

@@ -9,20 +9,20 @@ int main()
         num--;
     }
 
-    num = 10;
-    do
-    {
-        cout << "num = " << num << endl;
-        num--;
-    }while (num > 0);
+    // num = 10;
+    // do
+    // {
+    //     cout << "num = " << num << endl;
+    //     num--;
+    // }while (num > 0);
 
-    num = 10;
-    while (num > 0)
-    {
-        cout << "num = " << num << endl;
-        num--;
-        if (num == 5)
-            break;
-    }
+    // num = 10;
+    // while (num > 0)
+    // {
+    //     if (num == 5)
+    //         break;
+    //     cout << "num = " << num << endl;
+    //     num--;
+    // }
     return 0;
 }