feat : added preprocessor and namespaces

0xNILADRI · 0xNILADRI · commit e33a39c1170c · 2021-06-15T01:50:45.000+05:30
diff --git a/16.Constants, Preprocessor Directives and Namespaces/1_demo_preprocessors.cpp b/16.Constants, Preprocessor Directives and Namespaces/1_demo_preprocessors.cpp
@@ -0,0 +1,16 @@
+# include<iostream>
+using namespace std;
+    
+#define max(x,y) (x>y?x:y)
+#define msg(x) #x
+#define pI 3.1425
+#ifndef pI
+      #define pI 3.1425
+#endif
+
+int main()
+{
+	cout<<pI<<endl;
+	cout<<max(10,12)<<endl;
+	cout<<msg(hello)<<endl; // converted to string
+}
diff --git a/16.Constants, Preprocessor Directives and Namespaces/2_demo_namespace.cpp b/16.Constants, Preprocessor Directives and Namespaces/2_demo_namespace.cpp
@@ -0,0 +1,28 @@
+# include<iostream>
+using namespace std;
+    
+namespace first
+{
+	void fun()
+	{
+		cout<<"first"<<endl;
+	}
+};
+
+namespace second
+{
+	void fun()
+	{
+		cout<<"second"<<endl;
+	}
+};
+
+using namespace first;
+
+int main()
+{
+	fun(); // by default first fun is used due to namespace
+    second::fun();
+	std::cout<<"Used namespace cout::std"<<endl;
+    return 0;
+}
