using namespace std; : namespace « Language Basics « C++ Tutorial

1.	Language Basics
2.	Data Types
3.	Operators statements
4.	Array
5.	Development
6.	Exceptions
7.	Function
8.	Structure
9.	Class
10.	Operator Overloading
11.	Pointer
12.	File Stream
13.	template
14.	STL Introduction
15.	string
16.	vector
17.	list
18.	bitset
19.	set multiset
20.	valarray
21.	queue stack
22.	deque
23.	map multimap
24.	STL Algorithms Modifying sequence operations
25.	STL Algorithms Non modifying sequence operations
26.	STL Algorithms Binary search
27.	STL Algorithms Sorting
28.	STL Algorithms Merge
29.	STL Algorithms Min Max
30.	STL Algorithms Iterator
31.	STL Algorithms Heap
32.	STL Algorithms Helper

1.9.10.using namespace std;

#include <iostream>

using namespace std;



int main()

{

   // Print hello world on the screen

   cout << "Hello World";

   return 0;

}

Hello World"

1.9.namespace
	1.9.1.	A namespace
	1.9.2.	Use a namespace
	1.9.3.	A nested namespace
	1.9.4.	Reuse namespace
	1.9.5.	Reference variables in namespaces
	1.9.6.	using namespace in program block
	1.9.7.	Reference global variable, variable in the nested namespace
	1.9.8.	Use Namespace to organize functions
	1.9.9.	function in a namespace reference variables in the same namespace
	1.9.10.	using namespace std;
	1.9.11.	Use function defined in a namespace
	1.9.12.	Using unnamed namespaces.
	1.9.13.	Using namespace aliases
	1.9.14.	Using the using directive

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