What is the difference between these function callings?

Question

So I was wondering what is the difference between these:

var a=5;
var b=3;
function asd(a,b) {
 a=a+b;
 b=b-a;
}
function asd2(){
 a=a+b;
 b=b-a;
}
function asd3(var a, var b){
 a=a+b;
 b=b-a;
}

Sorry for the lame question, but didn't know how to google is :S.

Answer 1

the first takes the parameters from the function arguments,

the second takes the global defined vars.

the third should not work.

• godzsa: but how does the first affect the a,b variables?
• cocco: it simply does not consider the global variables.
• cocco: if you call the first function without parameters you get 2 undefined values

Answer 2

I hope this isn't a homework question, but I'll point you in the right direction.

What is the output of:

asd(123,456);

Can you change the output of

asd2();

if so, how?

to tell the difference between asd() and asd3() try this:

var c=10;
var d=4;
alert (asd(c,d));
alert ("c is " + c + " and d is " + d);

versus

var c=10;
var d=4;
alert(asd3(c,d));
alert ("c is " + c + " and d is " + d);

• godzsa: no this is not a homework... I'm trying to write scripts for fun