default constructor was added.

CPlusPlus20ForProgrammers-master/examples/vector/main01_shapes_defaultConstructor.cpp

@@ -0,0 +1,16 @@
+#include "shapes_defaultConstructor.h"
+#include <iostream>
+
+int main(){
+  Cube a(1.0);
+  Cube b(3.0);
+ 
+//  Cube d{Cube()};
+  Cube c(a);
+
+  c[0] = 100.0;
+
+  std::cout << "a.data-->"<< a[0] << " c.data--->" << c[0];
+
+return 0;
+}

CPlusPlus20ForProgrammers-master/examples/vector/shapes_defaultConstructor.cpp

@@ -0,0 +1,39 @@
+
+#include "shapes_defaultConstructor.h"
+
+
+double& Cube::operator() (int i){
+        try {
+           if(i==1)
+            return L;
+           if (i==2)
+             return W;
+           if (i==3)
+             return H;
+           if (i<1 || i > 3)
+                   throw(i);
+        }
+        catch(int i){
+                      std::cout << "out of index" << i << "\n";
+                      exit(0);
+        }
+        return tmp;
+      }
+
+
+Cube::Cube(double _L , double _W , double _H, long int _N  ):N(_N){
+   SetL(_L); 
+   Data = new double[N];
+   Data[0] = _L;
+   //std::cout << "Constructor was run!\n";
+}
+
+
+
+void Cube::SetL(double _L){
+     L = _L;
+}
+
+const double& Cube::GetL()  {
+	return L;
+}

CPlusPlus20ForProgrammers-master/examples/vector/shapes_defaultConstructor.h

@@ -0,0 +1,23 @@
+#include <iostream>
+
+class Cube {
+  public:
+explicit  Cube(double _L = 0, double _W = 0, double _H = 0, long int N = 1);
+
+    	 ~Cube(){
+		     std::cout << "Destructor was run!\n";
+		     delete [] Data;
+    	}
+      void SetL(double _L);
+
+      const double& GetL();
+      double& operator() (int i);
+      double& operator[] (int i){return Data[i];};
+
+  private:
+      double L,W,H;
+      double* Data;
+      double tmp;
+      int N ;
+};
+

CPlusPlus20ForProgrammers-master/examples/vector/vector.h

@@ -14,25 +14,21 @@ class vector{
 	}
 		;
      protected:
-        T** data;	
+        T* data;	
 	int N;	
 };
 
 
 template <typename T>
 vector<T>::vector(int _N, T _Val ):N(_N){
-    data = new T*[N];
+    data = new T[N];
     for (int i{0}; i < N; i++){
-	    data[i] = new T(_Val);
+	    data[i] = T(_Val);
     }
 }
 
 template <typename T>
 vector<T>::~vector(){
-	for (int i{0};i < N; i++){
-		delete data[i];
-		std :: cout << i << "\n";
-	}
 	delete [] data;
 }
 
@@ -40,7 +36,7 @@ template <typename T>
 T vector<T>::operator[] (int i){
 	try {
 		if (i>=0 && i < N){
-			return *data[i];
+			return data[i];
 		}
 		else
 		 throw(i);

CPlusPlus20ForProgrammers-master/examples/vector/vector_pointer.h

@@ -0,0 +1,58 @@
+#include <iostream>
+
+namespace myspace {
+template <typename T>
+class vector{
+     public:
+	vector(){}
+	vector(int _N, T _Val);
+	~vector();
+	T operator[] (int i);
+	void resize();
+	int size(){
+		return N;
+	}
+		;
+     protected:
+        T** data;	
+	int N;	
+};
+
+
+template <typename T>
+vector<T>::vector(int _N, T _Val ):N(_N){
+    data = new T*[N];
+    for (int i{0}; i < N; i++){
+	    data[i] = new T(_Val);
+    }
+}
+
+template <typename T>
+vector<T>::~vector(){
+	for (int i{0};i < N; i++){
+		delete data[i];
+		std :: cout << i << "\n";
+	}
+	delete [] data;
+}
+
+template <typename T>
+T vector<T>::operator[] (int i){
+	try {
+		if (i>=0 && i < N){
+			return *data[i];
+		}
+		else
+		 throw(i);
+	}
+		catch(int i){
+			std::cout << "out of range, try to access "<< i << " out of " << N <<"\n";
+			exit(-1);
+		}
+	}
+	
+/// end of namespace ///
+}
+
+
+