JavaScript function to add an idefinite amount of numbers

Naked In Public · 06-06-2013 9:55pm #1

I'm a newbie to programming and I'm trying to make a recursive function that will add an indefinite amount of numbers. The code below shows the kind of thing I'm trying. I know it's not right because 'arguments' isn't strictly an array so you can't use 'shift()' with it.

Is there some way to get it to work in the way I want?

function adder() {
       
    if (arguments.length == 1) {return arguments[0];}
    else {return arguments[0] + adder(arguments.shift());}
}

Naked In Public · 06-06-2013 9:59pm

I know how to do it iteratively but is it possible to do recursively?

function adder() {
       
    var sum = 0;   
       
    for (var i=0; i<arguments.length; i++) {
        
        sum += arguments[i];
    }
    
    return sum;
}

Naked In Public · 06-06-2013 10:15pm

What if I pass the values as an array and then use 'shift()' on the element 'argument[0]' instead the whole arguments object?

Naked In Public · 06-06-2013 10:20pm

I just tried this code:

function adder() {
       
    if (arguments[0].length == 1) {return arguments[0][0];}
    else {return arguments[0][0] + adder(arguments[0].shift());}
}

It works if I pass it an array with one element. Any bigger and nothing happens.

Naked In Public · 06-06-2013 10:39pm

I tried replacing the recursive mention of 'adder' with 'arguments.callee', but still no joy.

function adder() {
       
    if (arguments[0].length == 1) {return arguments[0][0];}
    else {return arguments[0][0] + arguments.callee(arguments[0].shift());}
}

Naked In Public · 06-06-2013 11:30pm

Ah, wait. Using arrays isn't the way I want to to go. I want the function to be able to operate on an arbitrary number of inputs.

DonkeyStyle \o/ · 07-06-2013 4:04am

Here's my effort, I dunno if it's so expensive that it defeats the point. And I wouldn't call it arbitrary exactly, since the stack will shit itself trying to add 50,000 numbers like this (where a simple loop seems happy).

[HTML]<html><head></head><body>

<script type="text/javascript">

alert(adder(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15));

function adder() {

// Convert arguments to array/object or copy if already an array
if(typeof arguments[0] == 'number') {
var args = Array.prototype.slice.call(arguments);
} else {
var args = arguments[0];
}

//console.log(args);

// Adding stuff
if(args.length == 1) {
return args[0];
} else {
args[0] += args.pop();
return adder(args);
}

}

</script>
</body></html>[/HTML]

Naked In Public · 07-06-2013 7:34pm

Is it possible to cut the first argument from the arguments object and then pass it on?

JavaScript function to add an idefinite amount of numbers

Comments