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JavaScript Tutorial

Javascript Functions

Functions are the block of code that we want to use again and again simply by calling with their name.

You can make your own functions and use them whenever and wherever you want just simple by making a function and calling that function.

function functionName() 
{
    Your code here;
}

//For calling your function
functionName();

function demo()
{
  alert( "Hello Javascript" );
}
demo();

This will display Hello Javascript.

function functionName(parameters) 
{
    your code here
}

/*For calling your function*/
functionName(parameter);

You can send as many parameters in function as you want.

function demo(val)
{
  alert( "Here is your value is "+val);
}

demo(10);

This will display Here is your value 10.

function demo(val)
{
  var add=val+10;
  return add;
}

var val2 = demo(10);
alert( "Here is your value "+val2 );

This will display Here is your value 20.