Difference between revisions of "Hello World"

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(Created page with "<syntaxhighlight lang="cpp" line> #include <iostream> int main() { std::cout << "Hello World!"; } </syntaxhighlight> Line 1: #include <iostream><br/> Lines beginning with a...")
 
(Note - Improvement)
 
(4 intermediate revisions by 3 users not shown)
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=Using Visual Studio=
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Create a new project in Visual Studio, and choose 'C++' and I would recommend using the 'Empty Project'.
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Now in the interface, find 'Solution Explorer':
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[[File:CPPSE.png]]
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You will notice a section for 'Header' files and a section for 'Source' files. Right click on the 'Source Files' and choose Add, and then new item. Choose a Source file, and call it 'main.cpp'.
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=Helloworld=
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Now type the following into your 'main.cpp' file:
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<syntaxhighlight lang="cpp" line>
 
<syntaxhighlight lang="cpp" line>
 
#include <iostream>
 
#include <iostream>
Line 4: Line 17:
 
int main()
 
int main()
 
{
 
{
   std::cout << "Hello World!";
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   std::cout << "Hello World!" << std::endl;
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  return 0; // Must return an integer (int main)
 
}
 
}
 
</syntaxhighlight>
 
</syntaxhighlight>
Line 1: #include <iostream><br/>
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'''Line 1: #include <iostream><br/>'''
 
Lines beginning with a hash sign (#) are directives read and interpreted by what is known as the preprocessor. They are special lines interpreted before the compilation of the program itself begins. In this case, the directive #include <iostream>, instructs the preprocessor to include a section of standard C++ code, known as header iostream, that allows to perform standard input and output operations, such as writing the output of this program (Hello World) to the screen.
 
Lines beginning with a hash sign (#) are directives read and interpreted by what is known as the preprocessor. They are special lines interpreted before the compilation of the program itself begins. In this case, the directive #include <iostream>, instructs the preprocessor to include a section of standard C++ code, known as header iostream, that allows to perform standard input and output operations, such as writing the output of this program (Hello World) to the screen.
  
Line 5: std::count << "Hello World!";<br/>
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'''Line 5: std::cout << "Hello World!" << std::endl;<br/>'''
 
This statement has three parts: First, std::cout, which identifies the Standard Character output Device (usually, this is the computer screen). Second, the insertion operator (<<), which indicates that what follows is inserted into std::cout. Finally, a sentence within quotes ("Hello world!"), is the content inserted into the standard output.
 
This statement has three parts: First, std::cout, which identifies the Standard Character output Device (usually, this is the computer screen). Second, the insertion operator (<<), which indicates that what follows is inserted into std::cout. Finally, a sentence within quotes ("Hello world!"), is the content inserted into the standard output.
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===Note - Improvement===
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Note one doesn't have to use the :: (namespace) operator, if need be one can set a using directive for the namespace so everything contained within the namespace is accessible directly from the scope of the file.
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<syntaxhighlight lang="cpp" line>
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#include <iostream>
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using namespace std; // added line so std:: not required lower down
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int main()
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{
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  cout << "Hello World!" << endl;
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  return 0; // Must return an integer (int main)
 +
}
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</syntaxhighlight>
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 +
in this case std::cout is no longer required & one can just use the keyword cout.

Latest revision as of 10:50, 13 June 2019

Using Visual Studio

Create a new project in Visual Studio, and choose 'C++' and I would recommend using the 'Empty Project'.

Now in the interface, find 'Solution Explorer':

CPPSE.png

You will notice a section for 'Header' files and a section for 'Source' files. Right click on the 'Source Files' and choose Add, and then new item. Choose a Source file, and call it 'main.cpp'.

Helloworld

Now type the following into your 'main.cpp' file:

1 #include <iostream>
2 
3 int main()
4 {
5   std::cout << "Hello World!" << std::endl;
6   return 0; // Must return an integer (int main)
7 }

Line 1: #include <iostream>
Lines beginning with a hash sign (#) are directives read and interpreted by what is known as the preprocessor. They are special lines interpreted before the compilation of the program itself begins. In this case, the directive #include <iostream>, instructs the preprocessor to include a section of standard C++ code, known as header iostream, that allows to perform standard input and output operations, such as writing the output of this program (Hello World) to the screen.

Line 5: std::cout << "Hello World!" << std::endl;
This statement has three parts: First, std::cout, which identifies the Standard Character output Device (usually, this is the computer screen). Second, the insertion operator (<<), which indicates that what follows is inserted into std::cout. Finally, a sentence within quotes ("Hello world!"), is the content inserted into the standard output.

Note - Improvement

Note one doesn't have to use the :: (namespace) operator, if need be one can set a using directive for the namespace so everything contained within the namespace is accessible directly from the scope of the file.

1 #include <iostream>
2 using namespace std; // added line so std:: not required lower down
3 
4 int main()
5 {
6   cout << "Hello World!" << endl;
7   return 0; // Must return an integer (int main)
8 }

in this case std::cout is no longer required & one can just use the keyword cout.