Question

I just have a small question that I would like some clarification about, if I have created a function that is set up to accept 2 parameters and then perform some calculation but then I realise that the function I have created could also be used in another part of my code but will need to accept an additional parameter, how can use the function but pass in an additional parameter?

Regards
Kyle

Answer 1

You basically create a function function with any number of parameters and call them by passing any number of parameters.

For example:

    function Test(a,b,c)
    {
    }


 //callling Test
  Test(1)
  Test(1,2)  // now inside Function Test c will be undefined
  Test(1,2,3)
  Test(1,2,3,4) // note here i have passed an additonal paramter that will be totally ignored

You can create a calculator like below

function Calculate(num1, num2, operation)
{
operation= operation || 'sum'; //sum is the default operator
if(operation == 'sum')
{
return num1 + num2 ;
}
if(operation == 'multiply')
{
return num1 * num2 ;
}
if(operation == 'subtract')
{
return num1 - num2 ;
}
if(operation == 'divide')
{
return num1 / num2 ;
}
}


Calculate(1, 2)  //returns 3  -- defaut operator is picked
Calculate(1, 2, 'sum')  //returns 3
Calculate(1, 2, 'multiply')  //returns 2