A function is a group of statements that together perform a specific task. You can write all intended functionality at one place and call it wherever required.

Why use function ?

Function are used for divide a large code into module, due to this we can easily debug and maintain the code. For example if we write a calculator programs at that time we can write every logic in a separate function (For addition sum(), for subtraction sub()). Any function can be called many times.

Defining a function:

return_type  function_name(parameter) 
{ 
function body; 
}

Calling a function:

function_name();  
OR   
variable=function_name(argument);

Advantage of Function:

• Code Re-usability
• Develop an application in module format.
• Easily to debug the program.
• Code optimization: No need to write lot of code.
• Length of the source code can be reduced.